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Mathematics Higher level

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Mathematics higher level paper 3 specimen markscheme. CALCULUS. Mathematics higher ... 4 pages. 1 hour. © International Baccalaureate Organization 2012 ...
Mathematics Higher level

Specimen paper 3

For first examinations in 2014

CONTENTS DISCRETE MATHEMATICS Mathematics higher level paper 3 specimen question paper Mathematics higher level paper 3 specimen markscheme CALCULUS Mathematics higher level paper 3 specimen question paper Mathematics higher level paper 3 specimen markscheme SETS, RELATIONS AND GROUPS Mathematics higher level paper 3 specimen question paper Mathematics higher level paper 3 specimen markscheme STATISTICS AND PROBABILITY Mathematics higher level paper 3 specimen question paper Mathematics higher level paper 3 specimen markscheme

SPEC/5/MATHL/HP3/ENG/TZ0/DM

MATHEMATICS HIGHER LEVEL PAPER 3 – DISCRETE MATHEMATICS SPECIMEN 1 hour INSTRUCTIONS TO CANDIDATES Do not open this examination paper until instructed to do so. Answer all the questions. Unless otherwise stated in the question, all numerical answers should be given exactly or correct to three significant figures. A graphic display calculator is required for this paper. A clean copy of the Mathematics HL and Further Mathematics HL formula booklet is required for this paper. The maximum mark for this examination paper is [60 marks].

4 pages © International Baccalaureate Organization 2012

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/DM

Please start each question on a new page. Full marks are not necessarily awarded for a correct answer with no working. Answers must be supported by working and/or explanations. In particular, solutions found from a graphic display calculator should be supported by suitable working, e.g. if graphs are used to may be given for a correct method, provided this is shown by written working. You are therefore advised to show all working. 1.

[Maximum mark: 9] [4 marks]

x+

2.

y=

[5 marks]

[Maximum mark: 13] G

P, Q, R, S, T

P P

0

Q R

R

T 2

0

0

0

0

0

0

0

0

0 2

S

0 0

S T

Q

0

G

[2 marks] G is

[4 marks] G enables you to state that it has an Eulerian trail and [2 marks]

(This question continues on the following page)

–3–

SPEC/5/MATHL/HP3/ENG/TZ0/DM

(Question 2 continued) G [1 mark] G [4 marks]

3.

[Maximum mark: 12] ap (i)

p Show that this result is not true when a =

p=

k 45

congruences 3 x

4.

[6 marks]

k

4 (mod 5) and x

[6 marks]

[Maximum mark: 12] G

A B C D E

A –

B

C

D

E

– – – – G

[4 marks]

G

G

[8 marks] Turn over

–4– 5.

SPEC/5/MATHL/HP3/ENG/TZ0/DM

[Maximum mark: 14] {un } , n ! + u =u =3 {vn } , n ! + v = 2 and v2 = n induction to show that vn

un

n

un + n

5un +

6un

vn +

4vn +

4vn

[6 marks]

[8 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

MARKSCHEME SPECIMEN

MATHEMATICS DISCRETE MATHEMATICS

Higher Level

Paper 3

9 pages

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

Instructions to Examiners Abbreviations M

Marks awarded for attempting to use a correct Method; working must be seen.

(M)

Marks awarded for Method; may be implied by correct subsequent working.

A

Marks awarded for an Answer or for Accuracy; often dependent on preceding M marks.

(A)

Marks awarded for an Answer or for Accuracy; may be implied by correct subsequent working.

R

Marks awarded for clear Reasoning.

N

Marks awarded for correct answers if no working shown.

AG

Answer given in the question and so no marks are awarded.

Using the markscheme 1

General Write the marks in red on candidates’ scripts, in the right hand margin. ! Show the breakdown of individual marks awarded using the abbreviations M1, A1, etc. ! Write down the total for each question (at the end of the question) and circle it.

2

Method and Answer/Accuracy marks ! Do not automatically award full marks for a correct answer; all working must be checked, and marks awarded according to the markscheme. ! It is not possible to award M0 followed by A1, as A mark(s) depend on the preceding M mark(s), if any. ! Where M and A marks are noted on the same line, e.g. M1A1, this usually means M1 for an attempt to use an appropriate method (e.g. substitution into a formula) and A1 for using the correct values. ! Where the markscheme specifies (M2), N3, etc., do not split the marks. ! Once a correct answer to a question or part-question is seen, ignore further working.

3

N marks Award N marks for correct answers where there is no working. ! Do not award a mixture of N and other marks. ! There may be fewer N marks available than the total of M, A and R marks; this is deliberate as it penalizes candidates for not following the instruction to show their working.

–3– 4

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

Implied marks Implied marks appear in brackets e.g. (M1), and can only be awarded if correct work is seen or if implied in subsequent working. ! Normally the correct work is seen or implied in the next line. ! Marks without brackets can only be awarded for work that is seen.

5

Follow through marks Follow through (FT) marks are awarded where an incorrect answer from one part of a question is used correctly in subsequent part(s). To award FT marks, there must be working present and not just a final answer based on an incorrect answer to a previous part. ! If the question becomes much simpler because of an error then use discretion to award fewer FT marks. ! If the error leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s). ! Within a question part, once an error is made, no further dependent A marks can be awarded, but M marks may be awarded if appropriate. ! Exceptions to this rule will be explicitly noted on the markscheme.

6

Mis-read If a candidate incorrectly copies information from the question, this is a mis-read (MR). Apply a MR penalty of 1 mark to that question. Award the marks as usual and then write –1(MR) next to the total. Subtract 1 mark from the total for the question. A candidate should be penalized only once for a particular mis-read. ! If the question becomes much simpler because of the MR, then use discretion to award fewer marks. ! If the MR leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s).

7

Discretionary marks (d) An examiner uses discretion to award a mark on the rare occasions when the markscheme does not cover the work seen. The mark should be labelled (d) and a brief note written next to the mark explaining this decision.

8

Alternative methods Candidates will sometimes use methods other than those in the markscheme. Unless the question specifies a method, other correct methods should be marked in line with the markscheme. If in doubt, contact your team leader for advice. ! Alternative methods for complete questions are indicated by METHOD 1, METHOD 2, etc. ! Alternative solutions for part-questions are indicated by EITHER . . . OR. ! Where possible, alignment will also be used to assist examiners in identifying where these alternatives start and finish.

–4– 9

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

Alternative forms Unless the question specifies otherwise, accept equivalent forms. ! As this is an international examination, accept all alternative forms of notation. ! In the markscheme, equivalent numerical and algebraic forms will generally be written in brackets immediately following the answer. ! In the markscheme, simplified answers, (which candidates often do not write in examinations), will generally appear in brackets. Marks should be awarded for either the form preceding the bracket or the form in brackets (if it is seen). Example: for differentiating f ( x) ! 2sin (5 x # 3) , the markscheme gives: f & ( x) ! $ 2cos (5 x # 3) % 5

$ ! 10cos (5 x # 3) %

A1

Award A1 for $ 2cos (5 x # 3) % 5 , even if 10cos (5 x # 3) is not seen. 10

Accuracy of Answers The method of dealing with accuracy errors on a whole paper basis by means of the Accuracy Penalty (AP) no longer applies. Instructions to examiners about such numerical issues will be provided on a question by question basis within the framework of mathematical correctness, numerical understanding and contextual appropriateness. The rubric on the front page of each question paper is given for the guidance of candidates. The markscheme (MS) may contain instructions to examiners in the form of “Accept answers which round to n significant figures (sf)”. Where candidates state answers, required by the question, to fewer than n sf, award A0. Some intermediate numerical answers may be required by the MS but not by the question. In these cases only award the mark(s) if the candidate states the answer exactly or to at least 2sf.

11

Crossed out work If a candidate has drawn a line through work on their examination script, or in some other way crossed out their work, do not award any marks for that work.

12

Calculators A GDC is required for paper 3, but calculators with symbolic manipulation features (e.g. TI-89) are not allowed. Calculator notation The Mathematics HL guide says: Students must always use correct mathematical notation, not calculator notation. Do not accept final answers written using calculator notation. However, do not penalize the use of calculator notation in the working.

13

More than one solution Where a candidate offers two or more different answers to the same question, an examiner should only mark the first response unless the candidate indicates otherwise.

–5– 1.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

581 " 2 ! 259 " 63 259 # 4 ! 63 " 7 63 # 9 ! 7 the GCD is therefore 7

M1A1 A1 A1 [4 marks]

(b)

consider 7 # 259 $ 4 ! 63 # 259 $ 4 ! (581 $ 2 ! 259) # 259 ! 9 " 581 ! ($4) the general solution is therefore x # 9 " 83n ; y # $4 $ 37 n where n % !

M1 A1 A1 M1A1

Notes: Accept solutions laid out in tabular form. Dividing the diophantine equation by 7 is an equally valid method. [5 marks] Total [9 marks]

–6– 2.

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

(a)

A2 [2 marks] (b)

(i)

G is not simple because 2 edges join P to T

R1

(ii)

G is connected because there is a path joining every pair of vertices

R1

(iii)

(P, R) and (Q, S, T) are disjoint vertices so G is bipartite

R1 A1

Note:

Award the A1 only if the R1 is awarded. [4 marks]

(c)

G has an Eulerian trail because it has two vertices of odd degree (R and T have degree 3), all the other vertices having even degree the following example is such a trail TPTRSPQR

R1 A1 [2 marks]

(d)

G has no Eulerian circuit because there are 2 vertices which have odd degree

R1 [1 mark]

(e)

consider

so it is possible to add 3 extra edges consider G with one of the edges PT deleted; this is a simple graph with 6 edges; on addition of the new edges, it will still be simple e ! 3v " 6 # e ! 3 $ 5 " 6 % 9 so at most 3 edges can be added

A1 M1 R1 R1 [4 marks] Total [13 marks]

–7– 3.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

(i)

28 ! 256 " 4(mod 9) (so not true) 9 is not prime

A1 A1

(ii)

consider various powers of 2, e.g. obtaining 26 ! 64 " 1(mod 9) therefore 245 ! (26 )7 # 23 " 8(mod 9) (so k ! 8 )

M1 A1 M1 A1 [6 marks]

(b)

EITHER the solutions to 3x " 4(mod5) are 3, 8, 13, 18, 23,… the solutions to 5 x " 6(mod 7) are 4, 11, 18,… 18 is therefore the smallest solution the general solution is 18 $ 35n , n % ! the required solutions are therefore 123, 158, 193

M1A1 A1 A1 M1 A1

OR 3x " 4(mod 5) & 2 # 3x " 2 # 4(mod5) & x " 3(mod 5) A1 & x ! 3 $ 5t M1 & 15 $ 25t " 6 (mod 7) & 4t " 5(mod 7) & 2 # 4t " 2 # 5(mod 7) & t " 3(mod 7) A1 & t ! 3 $ 7n A1 & x ! 3 $ 5(3 $ 7 n) ! 18 $ 35n M1 the required solutions are therefore 123, 158, 193 A1

OR using the Chinese remainder theorem formula method first convert the congruences to x " 3(mod 5) and x " 4(mod 7) M ! 35, M 1 ! 7 , M 2 ! 5, m1 ! 5, m2 ! 7 , a1 ! 3, a2 ! 4 x1 is the solution of M 1 x1 " 1(mod m1 ) , i.e. 7 x1 " 1(mod 5) so x1 ! 3 x2 is the solution of M 2 x2 " 1(mod m2 ) , i.e. 5 x2 " 1(mod 7) so x2 ! 3 a solution is therefore x ! a1 M 1 x1 $ a2 M 2 x2 ! 3 # 7 # 3 $ 4 # 5 # 3 ! 123 the general solution is 123 $ 35n , n % ! the required solutions are therefore 123, 158, 193

A1A1

M1 A1 M1 A1 [6 marks] Total [12 marks]

–8– 4.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

using the nearest neighbour algorithm, starting with A, A !"#!"! !$ C !%#!%! !& B !' the upper bound is therefore 9 ! 10 ! 16 ! 13 ! 11 " 59

A1 A1 A1 A1 [4 marks]

(b)

(i)

the edges are added in the order CE BD BE

A1 A1 A1

A1 (ii)

the weight of the minimum spanning tree is 37 we now reconnect A with the 2 edges of least weight i.e. AE and AB the lower bound is therefore 37 ! 9 ! 11 " 57

(A1) (M1) A1 A1 [8 marks] Total [12 marks]

–9– 5.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/DM/M

the auxiliary equation is m 2 ! 5m " 6 # 0 giving m # 2, 3 the general solution is un # A $ 2n " B $ 3n substituting n # 1, 2 2 A " 3B # 3 4 A " 9B # 3 the solution is A # 3, B # –1 giving un # 3 $ 2n ! 3n

M1 A1 A1 M1 A1 A1 [6 marks]

(b)

we first prove that vn # 2n (2n ! 1) for n # 1, 2 for n # 1 , it gives 2 $ 1 # 2 which is correct for n # 2 , it gives 4 $ 3 # 12 which is correct we now assume that the result is true for n % k consider vk 1 # 4vk ! 4vk 1 (k & 2) k

# 4.2 (2k ! 1) ! 4.2 #2

k 1

k 1

(2k ! 3)

(4k ! 2 ! 2k " 3)

k 1

# 2 ' 2 (k " 1) ! 1( this proves that if the result is true for n % k then it is true for n % k " 1 since we have also proved it true for n % 2 , the general result is proved by induction

Note:

M1 A1 M1 M1 A1 A1 A1

R1

A reasonable attempt has to be made to the induction step for the final R1 to be awarded. [8 marks] Total [14 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SE

MATHEMATICS HIGHER LEVEL PAPER 3 – CALCULUS SPECIMEN 1 hour INSTRUCTIONS TO CANDIDATES Do not open this examination paper until instructed to do so. Answer all the questions. Unless otherwise stated in the question, all numerical answers should be given exactly or correct to three significant figures. A graphic display calculator is required for this paper. A clean copy of the Mathematics HL and Further Mathematics HL formula booklet is required for this paper. The maximum mark for this examination paper is [60 marks].

3 pages © International Baccalaureate Organization 2012

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SE

Please start each question on a new page. Full marks are not necessarily awarded for a correct answer with no working. Answers must be supported by working and/or explanations. In particular, solutions found from a graphic display calculator should be supported by suitable working, e.g. if graphs are used to may be given for a correct method, provided this is shown by written working. You are therefore advised to show all working. 1.

[Maximum mark: 14] by f ( x) = ln (1 + sin x) . , 2 2

The function f 1 . (1 + sin x)

f ( x)

[4 marks] x4 .

f ( x) f

[7 marks]

x

2.

0

ln (1 sin x) x . x2

[3 marks]

[Maximum mark: 8]

x

dy dx

y

x2

y2 , x

0, x 2

y2 . [1 mark] y = f ( x) .

[7 marks]

–3– 3.

SPEC/5/MATHL/HP3/ENG/TZ0/SE

[Maximum mark: 15]

dy = dx

x

+y

y =1

x

y is 0,

2

x =0.

. x=0 3

x .

y

[6 marks]

e x (sin x + cos x) 1 e x cos x dx = e x (sin x + cos x) + c . 2 y = f ( x) .

4.

[9 marks]

[Maximum mark: 10] Let f ( x)

2x

x , x !. f

(0, 0) . a a

5.

f ( x ) dx

a

0.

[7 marks] [3 marks]

[Maximum mark: 13] (n 1) x n . 2 2n n =1 n [4 marks] [9 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

MARKSCHEME SPECIMEN

MATHEMATICS CALCULUS

Higher Level

Paper 3

9 pages

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

Instructions to Examiners Abbreviations M

Marks awarded for attempting to use a correct Method; working must be seen.

(M)

Marks awarded for Method; may be implied by correct subsequent working.

A

Marks awarded for an Answer or for Accuracy; often dependent on preceding M marks.

(A)

Marks awarded for an Answer or for Accuracy; may be implied by correct subsequent working.

R

Marks awarded for clear Reasoning.

N

Marks awarded for correct answers if no working shown.

AG

Answer given in the question and so no marks are awarded.

Using the markscheme 1

General Write the marks in red on candidates’ scripts, in the right hand margin. ! Show the breakdown of individual marks awarded using the abbreviations M1, A1, etc. ! Write down the total for each question (at the end of the question) and circle it.

2

Method and Answer/Accuracy marks ! Do not automatically award full marks for a correct answer; all working must be checked, and marks awarded according to the markscheme. ! It is not possible to award M0 followed by A1, as A mark(s) depend on the preceding M mark(s), if any. ! Where M and A marks are noted on the same line, e.g. M1A1, this usually means M1 for an attempt to use an appropriate method (e.g. substitution into a formula) and A1 for using the correct values. ! Where the markscheme specifies (M2), N3, etc., do not split the marks. ! Once a correct answer to a question or part-question is seen, ignore further working.

3

N marks Award N marks for correct answers where there is no working. ! Do not award a mixture of N and other marks. ! There may be fewer N marks available than the total of M, A and R marks; this is deliberate as it penalizes candidates for not following the instruction to show their working.

–3– 4

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

Implied marks Implied marks appear in brackets e.g. (M1), and can only be awarded if correct work is seen or if implied in subsequent working. ! Normally the correct work is seen or implied in the next line. ! Marks without brackets can only be awarded for work that is seen.

5

Follow through marks Follow through (FT) marks are awarded where an incorrect answer from one part of a question is used correctly in subsequent part(s). To award FT marks, there must be working present and not just a final answer based on an incorrect answer to a previous part. ! If the question becomes much simpler because of an error then use discretion to award fewer FT marks. ! If the error leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s). ! Within a question part, once an error is made, no further dependent A marks can be awarded, but M marks may be awarded if appropriate. ! Exceptions to this rule will be explicitly noted on the markscheme.

6

Mis-read If a candidate incorrectly copies information from the question, this is a mis-read (MR). Apply a MR penalty of 1 mark to that question. Award the marks as usual and then write –1(MR) next to the total. Subtract 1 mark from the total for the question. A candidate should be penalized only once for a particular mis-read. ! If the question becomes much simpler because of the MR, then use discretion to award fewer marks. ! If the MR leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s).

7

Discretionary marks (d) An examiner uses discretion to award a mark on the rare occasions when the markscheme does not cover the work seen. The mark should be labelled (d) and a brief note written next to the mark explaining this decision.

8

Alternative methods Candidates will sometimes use methods other than those in the markscheme. Unless the question specifies a method, other correct methods should be marked in line with the markscheme. If in doubt, contact your team leader for advice. ! Alternative methods for complete questions are indicated by METHOD 1, METHOD 2, etc. ! Alternative solutions for part-questions are indicated by EITHER . . . OR. ! Where possible, alignment will also be used to assist examiners in identifying where these alternatives start and finish.

–4– 9

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

Alternative forms Unless the question specifies otherwise, accept equivalent forms. ! As this is an international examination, accept all alternative forms of notation. ! In the markscheme, equivalent numerical and algebraic forms will generally be written in brackets immediately following the answer. ! In the markscheme, simplified answers, (which candidates often do not write in examinations), will generally appear in brackets. Marks should be awarded for either the form preceding the bracket or the form in brackets (if it is seen). Example: for differentiating f ( x) ! 2sin (5 x # 3) , the markscheme gives: f & ( x) ! $ 2cos (5 x # 3) % 5

$ ! 10cos (5 x # 3) %

A1

Award A1 for $ 2cos (5 x # 3) % 5 , even if 10cos (5 x # 3) is not seen. 10

Accuracy of Answers The method of dealing with accuracy errors on a whole paper basis by means of the Accuracy Penalty (AP) no longer applies. Instructions to examiners about such numerical issues will be provided on a question by question basis within the framework of mathematical correctness, numerical understanding and contextual appropriateness. The rubric on the front page of each question paper is given for the guidance of candidates. The markscheme (MS) may contain instructions to examiners in the form of “Accept answers which round to n significant figures (sf)”. Where candidates state answers, required by the question, to fewer than n sf, award A0. Some intermediate numerical answers may be required by the MS but not by the question. In these cases only award the mark(s) if the candidate states the answer exactly or to at least 2sf.

11

Crossed out work If a candidate has drawn a line through work on their examination script, or in some other way crossed out their work, do not award any marks for that work.

12

Calculators A GDC is required for paper 3, but calculators with symbolic manipulation features (e.g. TI-89) are not allowed. Calculator notation The Mathematics HL guide says: Students must always use correct mathematical notation, not calculator notation. Do not accept final answers written using calculator notation. However, do not penalize the use of calculator notation in the working.

13

More than one solution Where a candidate offers two or more different answers to the same question, an examiner should only mark the first response unless the candidate indicates otherwise.

–5–

1.

cos x 1 " sin x # sin x (1 " sin x) # cos x cos x f $$( x) ! (1 " sin x)2

(a)

f "( x) !

# sin x # (sin 2 x " cos 2 x) (1 " sin x) 2 1 !# 1 " sin x !

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

A1 M1A1 A1 AG [4 marks]

(b)

(i)

f $$$( x) !

cos x (1 " sin x) 2

A1

# sin x (1 " sin x) 2 # 2(1 " sin x) cos 2 x (1 " sin x)4 f (0) ! 0, f $(0) ! 1, f $$(0) ! #1 f $$$(0) ! 1, f (4) (0) ! #2 f (4) ( x) !

2

f ( x) ! x #

(ii)

3

M1A1 M1 A1

4

x x x " # "% 2 6 12

the series contains even and odd powers of x

A1 R1 [7 marks]

x 2 x3 " "%# x ln (1 " sin x) # x 2 6 lim ! lim 2 x 0 x 0 x x2 #1 x " "% ! lim 2 6 x 0 1 1 !# 2 x#

(c)

Note:

M1

(A1) A1

Use of l’Hopital’s Rule is also acceptable. [3 marks] Total [14 marks]

–6– 2.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

the equation can be rewritten as 2

dy y ! x 2 " y 2 y # y$ % % ! 1" & ' dx x x ( x) so the differential equation is homogeneous

A1 AG [1 mark]

(b)

put y % vx so that

dy dv %v!x dx dx

substituting, dv v ! x % v ! 1 " v2 dx dv dx * 1 " v2 % * x arcsin v % ln x ! C y % sin (ln x ! C ) x y % x sin (ln x ! C )

M1A1

M1 M1 A1 A1 A1 [7 marks] Total [8 marks]

–7– 3.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

we note that y (0) ! 1 and y"(0) ! 2 y"" ! 2e x # y" tan x # y sec 2 x y""(0) ! 3 y""" ! 2e x # y"" tan x # 2 y" sec 2 x # 2 y sec 2 x tan x y"""(0) ! 6 the maclaurin series solution is therefore 3x 2 y ! 1 # 2x # # x 3 #$ 2

A1 M1 A1 M1 A1 A1 [6 marks]

(b)

(i)

(ii)

d x % e (sin x # cos x) & ! e x (sin x # cos x) # e x (cos x ' sin x) dx ! 2e x cos x it follows that 1 x x ( e cos x dx ! 2 e (sin x # cos x) # c

the differential equation can be written as dy ' y tan x ! 2e x dx tan x dx ! eln cos x ! cos x IF ! e ( dy cos x ' y sin x ! 2e x cos x dx integrating, y cos x ! e x (sin x # cos x) # C y ! 1 when x ! 0 gives C ! 0 therefore y ! e x (1 # tan x)

M1 A1 AG

M1 M1A1 M1 A1 M1 A1 [9 marks] Total [15 marks]

–8– 4.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

we note that f (0) ! 0, f ( x) ! 3x for x ! 0 and f ( x) " x for x # 0 lim f ( x) " lim x " 0 x

0

x

0

M1A1

lim f ( x) " lim 3 x " 0

A1

since f (0) " 0 , the function is continuous when x " 0 f (0 $ h) % f (0) h lim " lim " 1 h 0 h 0 h h f (0 $ h) % f (0) 3h lim " lim "3 h 0 h 0 h h these limits are unequal so f is not differentiable when x " 0

AG

x

0

x

0

M1A1 A1 R1 AG [7 marks]

a

(b)

&

a

0

a

f ( x ) dx " & x d x $ & 3 x d x a

' x2 ( ") * +2, " a2

0

0

M1

a

a

' 3x 2 ( $) * + 2 ,0

A1 A1 [3 marks] Total [10 marks]

–9–

5.

(a)

using the ratio test,

SPEC/5/MATHL/HP3/ENG/TZ0/SE/M

un 1 nx n 1 n 2 2n " ! un (n " 1) 2 2n 1 (n # 1) x n $

n3 x ! 2 (n " 1) (n # 1) 2

un 1 x $ un 2 the radius of convergence R satisfies R $ 1 so R $ 2 2 lim

n

M1 A1 A1

A1 [4 marks]

(b)

considering x $ 2 for which the series is (n # 1) % n2 n 1 using the limit comparison test with the harmonic series 1 , which diverges % n 1 n consider u n #1 lim n $ lim $1 n 1 n n n the series is therefore divergent for x $ 2 when x $ #2 , the series is (n # 1) ! ( #1) n % 2 n n 1 this is an alternating series in which the n th term tends to 0 as n & ' x #1 consider f ( x) $ 2 x 2# x f (( x) $ 3 x this is negative for x ) 2 so the sequence * un + is eventually decreasing

M1

A1 A1

A1 M1 A1 R1

the series therefore converges when x $ #2 by the alternating series test

R1

the interval of convergence is therefore [– 2, 2[

A1 [9 marks] Total [13 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SG

MATHEMATICS HIGHER LEVEL PAPER 3 – SETS, RELATIONS AND GROUPS SPECIMEN 1 hour INSTRUCTIONS TO CANDIDATES Do not open this examination paper until instructed to do so. Answer all the questions. Unless otherwise stated in the question, all numerical answers should be given exactly or correct to three significant figures. A graphic display calculator is required for this paper. A clean copy of the Mathematics HL and Further Mathematics HL formula booklet is required for this paper. The maximum mark for this examination paper is [60 marks].

3 pages © International Baccalaureate Organization 2012

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SG

Please start each question on a new page. Full marks are not necessarily awarded for a correct answer with no working. Answers must be supported by working and/or explanations. In particular, solutions found from a graphic display calculator should be supported by suitable working, e.g. if graphs are used to may be given for a correct method, provided this is shown by written working. You are therefore advised to show all working. 1.

2.

[Maximum mark: 14] (a)

! + by aRb if and only if ab is even. Show that The relation R only one of the conditions for R

(b)

The relation S

! + by aSb if and only if a 2

[5 marks]

b 2 (mod 6) .

(i)

Show that S is an equivalence relation.

(ii)

For each equivalence class, give the four smallest members.

[9 marks]

[Maximum mark: 13] The binary operations " and

# + by

a " b = ab and a * b = a 2b 2 . Determine whether or not (a)

" is commutative;

[2 marks]

(b)

is associative;

[4 marks]

(c)

is distributive over " ;

[4 marks]

(d)

" has an identity element.

[3 marks]

–3– 3.

SPEC/5/MATHL/HP3/ENG/TZ0/SG

[Maximum mark: 16] The group {G , 7 } multiplication modulo 7. (a)

{1, 2, 3, 4, 5, 6} where

(i)

Write down the Cayley table for {G ,

(ii)

Determine whether or not {G ,

7

7

7

denotes

}.

} is cyclic.

(iii) Find the subgroup of G of order 3, denoting it by H . (iv) Identify the element of order 2 in G (b)

4.

H.

The group {K , $} and $ denotes composition of permutations. (i)

Show that {K , $} is non-Abelian.

(ii)

Giving a reason, state whether or not {G ,

7

} and {K , $} are isomorphic.

[Maximum mark: 9] The groups {G , *} and {H , "} G E A B C H

E E A B C

A A E C B

B B C A E

"

e e a

a a e

e a

C C B E A

By considering a suitable function from G to H , show that a surjective homomorphism

5.

[10 marks]

[Maximum mark: 8] H be a non-empty subset of G . Prove that {H , *} Let {G , *} is a group if H is closed under * .

[6 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

MARKSCHEME SPECIMEN

MATHEMATICS SETS, RELATIONS AND GROUPS

Higher Level

Paper 3

7 pages

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

Instructions to Examiners Abbreviations M

Marks awarded for attempting to use a correct Method; working must be seen.

(M)

Marks awarded for Method; may be implied by correct subsequent working.

A

Marks awarded for an Answer or for Accuracy; often dependent on preceding M marks.

(A)

Marks awarded for an Answer or for Accuracy; may be implied by correct subsequent working.

R

Marks awarded for clear Reasoning.

N

Marks awarded for correct answers if no working shown.

AG

Answer given in the question and so no marks are awarded.

Using the markscheme 1

General Write the marks in red on candidates’ scripts, in the right hand margin. ! Show the breakdown of individual marks awarded using the abbreviations M1, A1, etc. ! Write down the total for each question (at the end of the question) and circle it.

2

Method and Answer/Accuracy marks ! Do not automatically award full marks for a correct answer; all working must be checked, and marks awarded according to the markscheme. ! It is not possible to award M0 followed by A1, as A mark(s) depend on the preceding M mark(s), if any. ! Where M and A marks are noted on the same line, e.g. M1A1, this usually means M1 for an attempt to use an appropriate method (e.g. substitution into a formula) and A1 for using the correct values. ! Where the markscheme specifies (M2), N3, etc., do not split the marks. ! Once a correct answer to a question or part-question is seen, ignore further working.

3

N marks Award N marks for correct answers where there is no working. ! Do not award a mixture of N and other marks. ! There may be fewer N marks available than the total of M, A and R marks; this is deliberate as it penalizes candidates for not following the instruction to show their working.

–3– 4

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

Implied marks Implied marks appear in brackets e.g. (M1), and can only be awarded if correct work is seen or if implied in subsequent working. ! Normally the correct work is seen or implied in the next line. ! Marks without brackets can only be awarded for work that is seen.

5

Follow through marks Follow through (FT) marks are awarded where an incorrect answer from one part of a question is used correctly in subsequent part(s). To award FT marks, there must be working present and not just a final answer based on an incorrect answer to a previous part. ! If the question becomes much simpler because of an error then use discretion to award fewer FT marks. ! If the error leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s). ! Within a question part, once an error is made, no further dependent A marks can be awarded, but M marks may be awarded if appropriate. ! Exceptions to this rule will be explicitly noted on the markscheme.

6

Mis-read If a candidate incorrectly copies information from the question, this is a mis-read (MR). Apply a MR penalty of 1 mark to that question. Award the marks as usual and then write –1(MR) next to the total. Subtract 1 mark from the total for the question. A candidate should be penalized only once for a particular mis-read. ! If the question becomes much simpler because of the MR, then use discretion to award fewer marks. ! If the MR leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s).

7

Discretionary marks (d) An examiner uses discretion to award a mark on the rare occasions when the markscheme does not cover the work seen. The mark should be labelled (d) and a brief note written next to the mark explaining this decision.

8

Alternative methods Candidates will sometimes use methods other than those in the markscheme. Unless the question specifies a method, other correct methods should be marked in line with the markscheme. If in doubt, contact your team leader for advice. ! Alternative methods for complete questions are indicated by METHOD 1, METHOD 2, etc. ! Alternative solutions for part-questions are indicated by EITHER . . . OR. ! Where possible, alignment will also be used to assist examiners in identifying where these alternatives start and finish.

–4– 9

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

Alternative forms Unless the question specifies otherwise, accept equivalent forms. ! As this is an international examination, accept all alternative forms of notation. ! In the markscheme, equivalent numerical and algebraic forms will generally be written in brackets immediately following the answer. ! In the markscheme, simplified answers, (which candidates often do not write in examinations), will generally appear in brackets. Marks should be awarded for either the form preceding the bracket or the form in brackets (if it is seen). Example: for differentiating f ( x) ! 2sin (5 x # 3) , the markscheme gives: f & ( x) ! $ 2cos (5 x # 3) % 5

$ ! 10cos (5 x # 3) %

A1

Award A1 for $ 2cos (5 x # 3) % 5 , even if 10cos (5 x # 3) is not seen. 10

Accuracy of Answers The method of dealing with accuracy errors on a whole paper basis by means of the Accuracy Penalty (AP) no longer applies. Instructions to examiners about such numerical issues will be provided on a question by question basis within the framework of mathematical correctness, numerical understanding and contextual appropriateness. The rubric on the front page of each question paper is given for the guidance of candidates. The markscheme (MS) may contain instructions to examiners in the form of “Accept answers which round to n significant figures (sf)”. Where candidates state answers, required by the question, to fewer than n sf, award A0. Some intermediate numerical answers may be required by the MS but not by the question. In these cases only award the mark(s) if the candidate states the answer exactly or to at least 2sf.

11

Crossed out work If a candidate has drawn a line through work on their examination script, or in some other way crossed out their work, do not award any marks for that work.

12

Calculators A GDC is required for paper 3, but calculators with symbolic manipulation features (e.g. TI-89) are not allowed. Calculator notation The Mathematics HL guide says: Students must always use correct mathematical notation, not calculator notation. Do not accept final answers written using calculator notation. However, do not penalize the use of calculator notation in the working.

13

More than one solution Where a candidate offers two or more different answers to the same question, an examiner should only mark the first response unless the candidate indicates otherwise.

–5– 1.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

reflexive: if a is odd, a " a is odd so R is not reflexive symmetric: if ab is even then ba is even so R is symmetric transitive: let aRb and bRc; it is necessary to determine whether or not aRc for example 5R2 and 2R3 since 5 " 3 is not even, 5 is not related to 3 and R is not transitive

R1 R1 (M1) A1 R1 [5 marks]

(b)

(i)

reflexive: a 2 ! a 2 (mod 6) so S is reflexive 2

2

2

2

R1 2

2

2

2

symmetric: a ! b (mod 6) " 6 | (a # b ) " 6 | (b # a ) " b ! a (mod 6) R1 so S is symmetric M1 transitive: let aSb and bSc so that a 2 $ b 2 % 6M and b 2 $ c 2 % 6 N 2 2 it follows that a $ c % 6( M % N ) so aSc and S is transitive R1 S is an equivalence relation because it satisfies the three conditions AG (ii)

by considering the squares of integers (mod 6), the equivalence classes are {1, 5, 7, 11, '} {2, 4, 8, 10, '} {3, 9, 15, 21, '} {6, 12, 18, 24, '}

(M1) A1 A1 A1 A1 [9 marks] Total [14 marks]

2.

(a)

a ! b $ ab $ ba $ b ! a since a ! b $ b ! a it follows that ! is commutative

A1 R1 [2 marks]

(b)

a ( (b ( c ) $ a ( b 2 c 2 $ a 2 b 4 c 4 2 2

M1A1

4 4 2

( a ( b) ( c $ a b ( c $ a b c these are different, therefore ( is not associative

Note:

A1 R1

Accept numerical counter-example. [4 marks]

(c)

a ( (b ! c) $ a ( bc $ a 2bc 2 2

2 2

M1A1 2

(a ( b) ! (a ( c) $ a b ! a c $ a bc these are equal so ( is distributive over !

A1 R1 [4 marks]

(d)

the identity e would have to satisfy a ! e $ a for all a

M1

now a ! e $ ae $ a " e $ a therefore there is no identity element

A1 A1 [3 marks] Total [13 marks]

–6– 3.

(a)

(i)

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

the Cayley table is 1 2 3 4 5 6

1 1 2 3 4 5 6

2 2 4 6 1 3 5

3 3 6 2 5 1 4

4 4 1 5 2 6 3

5 5 3 1 6 4 2

6 6 5 4 3 2 1 A3

Note:

Deduct 1 mark for each error up to a maximum of 3.

(ii)

by considering powers of elements, it follows that 3 (or 5) is of order 6 so the group is cyclic

(M1) A1 A1

(iii)

we see that 2 and 4 are of order 3 so the subgroup of order 3 is {1, 2, 4} M1A1

(iv)

the element of order 2 is 6 the coset is {3, 5, 6}

A1 A1 [10 marks]

(b)

(i)

consider for example &1 2 3 ! " 1 2 3 ! " 1 2 3 ! $ %!$ %#$ % & 2 1 3 ' & 2 3 1' & 1 3 2 ' "1 2 3 ! " 1 2 3 ! " 1 2 3 ! $ %!$ %#$ % & 2 3 1 ' & 2 1 3 ' & 3 2 1'

Note:

Award M1A1M1A0 if both compositions are done in the wrong order.

Note:

Award M1A1M0A0 if the two compositions give the same result, if no further attempt is made to find two permutations which are not commutative.

these are different so the group is not Abelian (ii)

they are not isomorphic because {G , (7 } is Abelian and {K , !} is not

M1A1 M1A1

R1AG R1 [6 marks] Total [16 marks]

–7– 4.

SPEC/5/MATHL/HP3/ENG/TZ0/SG/M

consider the function f given by f (E ) ! e f ( A) ! e f ( B) ! a f (C ) ! a

M1A1

then, it has to be shown that f ( X * Y ) ! f ( X ) ! f (Y ) for all X , Y " G consider f # ( E or A) * ( E or A) $ ! f ( E or A) ! e ; f ( E or A) ! f ( E or A) ! e ! e ! e

M1A1

f # ( E or A) * ( B or C ) $ ! f ( B or C ) ! a ; f ( E or A) ! f ( B or C ) ! e ! a ! a

A1

f # ( B or C ) * ( B or C ) $ ! f ( E or A) ! e ; f ( B or C ) ! f ( B or C ) ! a ! a ! e

A1

since the groups are Abelian, there is no need to consider f # ( B or C ) * ( E or A) $ the required property is satisfied in all cases so the homomorphism exists Note:

(M1)

R1

A comprehensive proof using tables is acceptable.

the kernel is {E , A}

A1 [9 marks]

5.

the associativity property carries over from G closure is given let h " H and let n denote the order of h, (this is finite because G is finite) it follows that h n ! e , the identity element and since H is closed, e " H since h % h n 1 ! e it follows that h n 1 is the inverse, h 1 , of h and since H is closed, h 1 " H so each element of H has an inverse element the four requirements for H to be a group are therefore satisfied

R1 R1 M1 R1 R1 M1 R1 R1 AG [8 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SP

MATHEMATICS HIGHER LEVEL PAPER 3 – STATISTICS AND PROBABILITY SPECIMEN 1 hour INSTRUCTIONS TO CANDIDATES Do not open this examination paper until instructed to do so. Answer all the questions. Unless otherwise stated in the question, all numerical answers should be given exactly or correct to three significant figures. A graphic display calculator is required for this paper. A clean copy of the Mathematics HL and Further Mathematics HL formula booklet is required for this paper. The maximum mark for this examination paper is [60 marks].

5 pages © International Baccalaureate Organization 2012

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SP

Please start each question on a new page. Full marks are not necessarily awarded for a correct answer with no working. Answers must be supported by working and/or explanations. In particular, solutions found from a graphic display calculator should be supported by suitable working, e.g. if graphs are used to may be given for a correct method, provided this is shown by written working. You are therefore advised to show all working. 1.

[Maximum mark: 10] A shopper buys 12 apples from a market stall and weighs them with the following results (in grams). 117, 124, 129, 118, 124, 116, 121, 126, 118, 121, 122, 129 You may assume that this is a random sample from a normal distribution with mean and variance 2 . (a)

(c)

Determine unbiased estimates of

and

2

.

[3 marks]

.

[2 marks]

The stallholder claims that the mean weight of apples is 125 grams but the shopper claims that the mean is less than this. (i)

State suitable hypotheses for testing these claims.

(ii)

Calculate the p-value of the above sample.

(iii) Giving a reason, state which claim is supported by your p-value using [5 marks]

–3– 2.

SPEC/5/MATHL/HP3/ENG/TZ0/SP

[Maximum mark: 12] When Andrew throws a dart at a target, the probability that he hits it is throws a dart at the target, the probability that he hits the it is

1 ; when Bill 3

1 . Successive throws 4

are independent. One evening, they throw darts at the target alternately, starting with Andrew, and stopping as soon as one of their darts hits the target. Let X denote the total number of darts thrown. (a)

1 Write down the value of P ( X = 1) and show that P ( X = 2) = . 6

(b)

Show that the probability generating function for X is given by 2t + t 2 G (t ) = . 6 3t 2

(c)

3.

Hence determine E ( X ) .

[2 marks]

[6 marks] [4 marks]

[Maximum mark: 9] The weights of adult monkeys of a certain species are known to be normally distributed, the males with mean 30 kg and standard deviation 3 kg and the females with mean 20 kg and standard deviation 2.5 kg. (a)

Find the probability that the weight of a randomly selected male is more than twice the weight of a randomly selected female.

[5 marks]

probability that their total weight is less than 175 kg.

[4 marks]

Turn over

–4– 4.

SPEC/5/MATHL/HP3/ENG/TZ0/SP

[Maximum mark: 15] The students in a class take an examination in Applied Mathematics which consists of two papers. Paper 1 is in Mechanics and Paper 2 is in Statistics. The marks obtained by the students in Paper 1 and Paper 2 are denoted by ( x , y ) respectively and you may assume that the values of ( x , y ) form a random sample from a bivariate . The teacher wishes to determine whether or not there is a positive association between marks in Mechanics and marks in Statistics. (a)

State suitable hypotheses.

[1 mark]

The marks obtained by the 12 students who sat both papers are given in the following table. Student

A

B

C

D

E

F

G

H

I

J

K

L

x

52

47

82

69

38

50

72

46

23

60

42

53

y

55

44

79

62

41

37

71

44

31

45

47

49

state its p-value. (ii) (c)

(d)

Interpret your p-value in the context of the problem.

George obtained a mark of 63 on Paper 1 but was unable to sit Paper 2 because of illness. Predict the mark that he would have obtained on Paper 2.

[5 marks]

[4 marks]

Another class of 16 students sat examinations in Physics and Chemistry and whether or not this value suggests a positive association between marks in Physics and marks in Chemistry.

[5 marks]

–5– 5.

SPEC/5/MATHL/HP3/ENG/TZ0/SP

[Maximum mark: 14] The discrete random variable X has the following probability distribution, where 1 0< < . 3 x

1

2

P ( X = x) (a)

(b)

2

Determine E ( X ) and show that Var ( X ) 6

In order to estimate distribution of X . (i)

3 1 3 16

2

.

[4 marks]

, a random sample of n observations is obtained from the

Given that X denotes the mean of this sample, show that ˆ =3 X 1 4 is an unbiased estimator for and write down an expression for the ˆ variance of 1 in terms of n and .

(ii)

Let Y denote the number of observations that are equal to 1 in the sample. Show that Y has the binomial distribution B(n , ) and deduce that ˆ = Y is another unbiased estimator for . Obtain an expression for the 2 n variance of ˆ2 .

(iii) Show that Var ( ˆ1 ) < Var ( ˆ2 ) and state, with a reason, which is the more ˆ or ˆ . 1

2

[10 marks]

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

MARKSCHEME SPECIMEN

MATHEMATICS STATISTICS AND PROBABILITY

Higher Level

Paper 3

7 pages

–2–

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

Instructions to Examiners Abbreviations M

Marks awarded for attempting to use a correct Method; working must be seen.

(M)

Marks awarded for Method; may be implied by correct subsequent working.

A

Marks awarded for an Answer or for Accuracy; often dependent on preceding M marks.

(A)

Marks awarded for an Answer or for Accuracy; may be implied by correct subsequent working.

R

Marks awarded for clear Reasoning.

N

Marks awarded for correct answers if no working shown.

AG

Answer given in the question and so no marks are awarded.

Using the markscheme 1

General Write the marks in red on candidates’ scripts, in the right hand margin. ! Show the breakdown of individual marks awarded using the abbreviations M1, A1, etc. ! Write down the total for each question (at the end of the question) and circle it.

2

Method and Answer/Accuracy marks ! Do not automatically award full marks for a correct answer; all working must be checked, and marks awarded according to the markscheme. ! It is not possible to award M0 followed by A1, as A mark(s) depend on the preceding M mark(s), if any. ! Where M and A marks are noted on the same line, e.g. M1A1, this usually means M1 for an attempt to use an appropriate method (e.g. substitution into a formula) and A1 for using the correct values. ! Where the markscheme specifies (M2), N3, etc., do not split the marks. ! Once a correct answer to a question or part-question is seen, ignore further working.

3

N marks Award N marks for correct answers where there is no working. ! Do not award a mixture of N and other marks. ! There may be fewer N marks available than the total of M, A and R marks; this is deliberate as it penalizes candidates for not following the instruction to show their working.

–3– 4

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

Implied marks Implied marks appear in brackets e.g. (M1), and can only be awarded if correct work is seen or if implied in subsequent working. ! Normally the correct work is seen or implied in the next line. ! Marks without brackets can only be awarded for work that is seen.

5

Follow through marks Follow through (FT) marks are awarded where an incorrect answer from one part of a question is used correctly in subsequent part(s). To award FT marks, there must be working present and not just a final answer based on an incorrect answer to a previous part. ! If the question becomes much simpler because of an error then use discretion to award fewer FT marks. ! If the error leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s). ! Within a question part, once an error is made, no further dependent A marks can be awarded, but M marks may be awarded if appropriate. ! Exceptions to this rule will be explicitly noted on the markscheme.

6

Mis-read If a candidate incorrectly copies information from the question, this is a mis-read (MR). Apply a MR penalty of 1 mark to that question. Award the marks as usual and then write –1(MR) next to the total. Subtract 1 mark from the total for the question. A candidate should be penalized only once for a particular mis-read. ! If the question becomes much simpler because of the MR, then use discretion to award fewer marks. ! If the MR leads to an inappropriate value (e.g. sin ! " 1.5 ), do not award the mark(s) for the final answer(s).

7

Discretionary marks (d) An examiner uses discretion to award a mark on the rare occasions when the markscheme does not cover the work seen. The mark should be labelled (d) and a brief note written next to the mark explaining this decision.

8

Alternative methods Candidates will sometimes use methods other than those in the markscheme. Unless the question specifies a method, other correct methods should be marked in line with the markscheme. If in doubt, contact your team leader for advice. ! Alternative methods for complete questions are indicated by METHOD 1, METHOD 2, etc. ! Alternative solutions for part-questions are indicated by EITHER . . . OR. ! Where possible, alignment will also be used to assist examiners in identifying where these alternatives start and finish.

–4– 9

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

Alternative forms Unless the question specifies otherwise, accept equivalent forms. ! As this is an international examination, accept all alternative forms of notation. ! In the markscheme, equivalent numerical and algebraic forms will generally be written in brackets immediately following the answer. ! In the markscheme, simplified answers, (which candidates often do not write in examinations), will generally appear in brackets. Marks should be awarded for either the form preceding the bracket or the form in brackets (if it is seen). Example: for differentiating f ( x) ! 2sin (5 x # 3) , the markscheme gives: f & ( x) ! $ 2cos (5 x # 3) % 5

$ ! 10cos (5 x # 3) %

A1

Award A1 for $ 2cos (5 x # 3) % 5 , even if 10cos (5 x # 3) is not seen. 10

Accuracy of Answers The method of dealing with accuracy errors on a whole paper basis by means of the Accuracy Penalty (AP) no longer applies. Instructions to examiners about such numerical issues will be provided on a question by question basis within the framework of mathematical correctness, numerical understanding and contextual appropriateness. The rubric on the front page of each question paper is given for the guidance of candidates. The markscheme (MS) may contain instructions to examiners in the form of “Accept answers which round to n significant figures (sf)”. Where candidates state answers, required by the question, to fewer than n sf, award A0. Some intermediate numerical answers may be required by the MS but not by the question. In these cases only award the mark(s) if the candidate states the answer exactly or to at least 2sf.

11

Crossed out work If a candidate has drawn a line through work on their examination script, or in some other way crossed out their work, do not award any marks for that work.

12

Calculators A GDC is required for paper 3, but calculators with symbolic manipulation features (e.g. TI-89) are not allowed. Calculator notation The Mathematics HL guide says: Students must always use correct mathematical notation, not calculator notation. Do not accept final answers written using calculator notation. However, do not penalize the use of calculator notation in the working.

13

More than one solution Where a candidate offers two or more different answers to the same question, an examiner should only mark the first response unless the candidate indicates otherwise.

–5– 1.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

unbiased estimate of ! " 122 2

A1 2

unbiased estimate of " " 4.4406! " 19.7 Note:

(M1)A1

Award (M1)A0 for 4.44. [3 marks]

(b)

the 99 % confidence interval for ! is [118, 126]

A1A1 [2 marks]

(c)

(i)

H 0 : ! " 125; H1 : ! # 125

A1

(ii)

p-value " 0.0220

A2

(iii)

the shopper’s claim is supported because 0.0220 # 0.05

A1R1 [5 marks] Total [10 marks]

2.

(a)

1 3 2 1 P ( X " 2) " $ 3 4 1 " 6 P ( X " 1) "

A1 A1 AG [2 marks]

(b)

1 2 1 2 3 1 2 3 2 1 G (t ) " t % $ t 2 % $ $ t 3 % $ $ $ t 4 % ... 3 3 4 3 4 3 3 4 3 4 1 & 1 ' 1 & 1 ' " t ( 1 % t 2 %!) % t 2 ( 1 % t 2 % !) 3 * 2 + 6 * 2 + t t2 " 32 % 62 t t 1, 1, 2 2 2t % t 2 " 6 , 3t 2

M1A1 M1A1

A1A1

AG [6 marks]

(c)

(2 % 2t )(6 , 3t 2 ) % 6t (2t % t 2 ) (6 , 3t 2 ) 2 10 E ( X ) " G -(1) " 3

G-(t ) "

M1A1 M1A1 [4 marks] Total [12 marks]

–6– 3.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M

we are given that M ! N (30, 9) and F ! N (20, 6.25) let X " M ! 2 F ; X ! N (!10, 34) we require P ( X " 0) # 0.0432

M1A1A1 (M1) A1 [5 marks]

(b)

let Y # M 1 $ M 2 $ F1 $ F2 $ F3 $ F4 $ F5 ; Y ! N (160, 49.25) we require P (Y % 175) # 0.984

M1A1A1 A1 [4 marks] Total [9 marks]

4.

(a)

A1

H 0 : ! # 0; H1 : ! " 0

[1 mark] (b)

(i)

correlation coefficient # 0.905 p-value # 2.61 & 10 5

A2 A2

(ii)

very strong evidence to indicate a positive association between marks in Mechanics and marks in Statistics

R1 [5 marks]

(c)

the regression line of y on x is y # 8.71 $ 0.789 x George’s estimated mark on Paper 2 # 8.71 $ 0.789 & 63 # 58

(M1)A1 (M1) A1 [4 marks]

(d)

n!2 # 2.3019' 1! r2 degrees of freedom # 14 p-value # 0.0186' at the 1 % significance level, this does not indicate a positive association between the marks in Physics and Chemistry t#r

M1A1 (A1) A1 R1 [5 marks] Total [15 marks]

–7– 5.

(a)

SPEC/5/MATHL/HP3/ENG/TZ0/SP/M M1A1

E ( X ) # 1 ! ! " 2 ! 2! " 3(1 # 3! ) $ 3 # 4!

Var ( X ) $ 1 ! ! " 4 ! 2! " 9(1 # 3! ) # (3 # 4! ) $ 6! # 16!

2

2

M1A1 AG [4 marks]

(b)

(i)

3 # E ( X ) 3 # (3 # 4! ) E (!ˆ1 ) $ $ $! 4 4 so !ˆ1 is an unbiased estimator of ! 6! # 16! Var (!ˆ1 ) $ 16n

(ii)

(iii)

M1A1 AG

2

A1

each of the n observed values has a probability ! of having the value 1 R1 AG so Y ! B(n , ! ) E (Y ) n! E (!ˆ2 ) $ $ $! A1 n n n! (1 # ! ) ! (1 # ! ) Var (!ˆ2 ) $ $ M1A1 n2 n 6! # 16! 2 # 16! " 16! 2 Var (!ˆ1 ) # Var (!ˆ2 ) $ 16n #10! $ %0 16n !ˆ1 is the more efficient estimator since it has the smaller variance

M1 A1 R1 [10 marks] Total [14 marks]

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