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Jun 13, 2011 - It is given that x satisfies the equation ... write down the three other roots of this equation in trigonometrical form. ..... Use of quadratic formula.
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General Certificate of Education Advanced Level Examination June 2011

Mathematics

MFP2

Unit Further Pure 2 Monday 13 June 2011

9.00 am to 10.30 am

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For this paper you must have: * the blue AQA booklet of formulae and statistical tables. You may use a graphics calculator.

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Time allowed * 1 hour 30 minutes

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Instructions * Use black ink or black ball-point pen. Pencil should only be used for drawing. * Fill in the boxes at the top of this page. * Answer all questions. * Write the question part reference (eg (a), (b)(i) etc) in the left-hand margin. * You must answer the questions in the spaces provided. Do not write outside the box around each page. * Show all necessary working; otherwise marks for method may be lost. * Do all rough work in this book. Cross through any work that you do not want to be marked.

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Information * The marks for questions are shown in brackets. * The maximum mark for this paper is 75. Advice * Unless stated otherwise, you may quote formulae, without proof, from the booklet.

P38531/Jun11/MFP2 6/6/

MFP2

2

Draw on the same Argand diagram:

1 (a) (i)

the locus of points for which j z  2  5i j ¼ 5

(3 marks)

p 4

(3 marks)

(ii) the locus of points for which

argðz þ 2iÞ ¼

Indicate on your diagram the set of points satisfying both

(b)

j z  2  5i j 4 5 argðz þ 2iÞ ¼

and

p 4

(2 marks)

Use the definitions of cosh y and sinh y in terms of ey to show that

2 (a)

cosh x cosh y  sinh x sinh y ¼ coshðx  yÞ

(4 marks)

It is given that x satisfies the equation

(b)

coshðx  ln 2Þ ¼ sinh x (i)

5

Show that tanh x ¼ 7 .

(ii) Express x in the form

3 (a)

(b)

(4 marks) 1 ln a . 2

(2 marks)

Show that ðr þ 1Þ!  ðr  1Þ! ¼ ðr 2 þ r  1Þðr  1Þ!

(2 marks)

n X ðr 2 þ r  1Þðr  1Þ! ¼ ðn þ 2Þn!  2

(4 marks)

Hence show that

r¼1

(02)

P38531/Jun11/MFP2

3

The cubic equation

4

z 3  2z 2 þ k ¼ 0

ðk 6¼ 0Þ

has roots a, b and g. (a) (i)

Write down the values of a þ b þ g and ab þ bg þ ga .

(ii) Show that a 2 þ b 2 þ g 2 ¼ 4 .

(2 marks) (2 marks)

(iii) Explain why a 3  2a 2 þ k ¼ 0 .

(1 mark)

(iv) Show that a 3 þ b 3 þ g 3 ¼ 8  3k .

(2 marks)

Given that a 4 þ b 4 þ g 4 ¼ 0 :

(b) (i)

show that k ¼ 2 ;

(4 marks)

(ii) find the value of a 5 þ b 5 þ g 5 .

5 (a)

(3 marks)

The arc of the curve y 2 ¼ x 2 þ 8 between the points where x ¼ 0 and x ¼ 6 is rotated through 2p radians about the x-axis. Show that the area S of the curved surface formed is given by pffiffiffi ð 6 pffiffiffiffiffiffiffiffiffiffiffiffiffi x 2 þ 4 dx S ¼ 2 2p

(5 marks)

0

(b)

6 (a)

(b)

By means of the substitution x ¼ 2 sinh y , show that pffiffiffi pffiffiffi S ¼ pð24 5 þ 4 2 sinh1 3Þ

(8 marks)

ðk þ 1Þð4ðk þ 1Þ2  1Þ ¼ 4k 3 þ 12k 2 þ 11k þ 3

(2 marks)

Show that

Prove by induction that, for all integers n 5 1 , 12 þ 32 þ 52 þ ::: þ ð2n  1Þ2 ¼ 1 nð4n2  1Þ 3

Turn over

s

(03)

(6 marks)

P38531/Jun11/MFP2

4 7 (a) (i)

Use de Moivre’s Theorem to show that cos 5y ¼ cos5 y  10 cos3 y sin2 y þ 5 cos y sin4 y and find a similar expression for sin 5y .

(5 marks)

(ii) Deduce that

tan yð5  10 tan2 y þ tan4 yÞ tan 5y ¼ 1  10 tan2 y þ 5 tan4 y (b)

Explain why t ¼ tan

(3 marks)

p is a root of the equation 5 t 4  10t 2 þ 5 ¼ 0

and write down the three other roots of this equation in trigonometrical form. (3 marks) (c)

Deduce that p 2p pffiffiffi ¼ 5 tan tan 5 5

(5 marks)

END OF QUESTIONS

Copyright Ó 2011 AQA and its licensors. All rights reserved.

(04)

P38531/Jun11/MFP2

MFP2 Q

Solution 1(a)

Marks

Total

Comments

Im

Use average of whole question if 2 diagrams used

Re

(i) Circle correct centre touching x-axis

B1 B1 B1F

(ii) half-line through (0, –2) through point of contact of circle with x-axis

B1 B1 B1

(b) Inside circle On line

B1 B1F Total

2(a)

( e x + e − x ) ( e y + e− y ) − ( e x – e− x ) ( e y – e− y )

2 2 2 2 Correct expansions 1 – x– y = e x – y + e ( ) = cosh ( x − y ) 2

(

(b)(i)

)

3 2 8

ft errors in position of line and circle

M0 if sinh and cosh confused M1 for formula quoted correctly

M1A1

A1

Use of e xy A0 4

AG Alternative:

– sinh x sinh ( ln 2 )

5 cosh ( ln 2 ) =  4  any method 3  sinh ( ln 2 ) = 4  5 7 cosh x = sinh x 4 4 5 tanh x = 7

(ii)

Can be inferred

A1

cosh ( x – ln 2 ) = cosh x cosh ( ln 2 )

 1+ 1  x = ln  2 1 –  1 = ln 6 2

3

Circle in any position Must be shown ft incorrect centre

e x − ln 2 + e − x + ln 2 e x − e − x = M1 2 2

M1

Both correct

B1

5 x −x 7  or e − e = 5  5 e x + e− x 7 7

4

M1

A1 Total

ex or e − x + ln 2 = 2e −1 2 used B1

e x = 6 A1

A1F A1

e x− ln 2 =

AG

tanh x =

5 A1 7

Could be embedded in (b)(i)

2 10

MFP2 (cont) Q Solution 3(a) ( r + 1)! = ( r + 1) r ( r – 1)! Result

Marks M1 A1

(b) Attempt to use method of differences n

(r  r =1

2

+ r – 1) ( r – 1)! = ( n + 1)! + n! – 1! – 0!

(ii)

α

2

m1 A1

B1

= (  α ) 2 – 2 αβ

(b)(i)

3

AG

2 Used. Watch 2

AG

E1

1

eg α satisfies the cubic equation since it is a root. Accept z = α

M1

= 8 – 3k

A1

Or 2

α

B1

α

M1

Or

A1

ft on

= 2 α – k α 3

= 2 ( 8 – 3k ) – 2k

α

5

A1 = 2 α 4 – k  α 2

4

M1

Substitution of values = –8

A1 A1 Total

3 14

3

= (  α ) − 3 α  αβ + 3αβγ 3

AG

α 4 = 2α 3 – kα 4

α = − 2 (M1A0)

A1

= 2  α 2 − 3k

k =2 (ii)

4 6

M1

(iii) Clear explanation

α

Must be seen

B1

=4

(iv)

AG

A1

Total

α = 2  αβ = 0

2

Comments

M1

( n + 1)! = ( n + 1) n! ( n + 2 ) n! – 2 4(a)(i)

Total

AG

α

4

= ( α 2 ) − 2 ( αβ ) + 4αβγ α

α = − 2

2

2

MFP2 (cont) Q 5(a)

Solution

2y

Marks

dy = 2x dx

S = 2π

6

0

Total

Or

B1

y 1+

x2 dx y2

Comments –1 dy = x ( x 2 + 8) 2 dx

M1 for use of formula provided

M1 A1F

function of x A1 for substitution for

Eliminating all y

= 2 2π

(b)

6

0

x 2 + 4 dx

A1 dx = 2cosh θ dθ

5

AG

B1

S = 2 2 π  4sinh 2 x + 4 . 2coshθ dθ

)

For eliminating x completely and use of dθ , ie dθ attempted Use of cosh 2 θ – sinh 2 θ = 1 (ignore limits) Use of formula for cosh 2θ ; must be correct

M1

S = 2 2 π  2coshθ . 2coshθ dθ

m1

 ( cosh2θ + 1) dθ

m1

= 4 2π

dy (one slip) dx

m1

dx = 2cosh θ dθ or

(

dy is a dx

 sinh 2θ  = 4 2π  +θ   2 

B1F

Correct integration of a cosh 2θ + b

= 4 2 π [sinhθ coshθ + θ ]

m1

Use of sinh 2θ = 2sinh θ cosh θ Must be seen

M1

Or change limits

x = 4 2π   2

x2 x +1 + sinh –1  4 2 

6

0

= π  24 5 + 4 2 sinh –1 3

(

A1 Total

)

6(a) Expansion of ( k + 1) 4 ( k + 1) – 1 2

8 13

M1

= 4k 3 + 12k 2 + 11k + 3

AG

A1

Any valid method – first step correct 2

AG

(b) Assume true for n = k For n = k + 1 : k +1

1 2 k ( 4k 2 – 1) + ( 2k + 1) 3 1 = ( 4k 3 + 12k 2 +11k + 3) 3 1 2 = ( k + 1) 4 ( k + 1) – 1 3 True for n = 1 shown Proof by induction set out properly (if factorised by 3 linear factors, allow A1 at this particular point) Total

( 2r – 1)  r =1

2

=

(

)

M1A1

No LHS M1A0

A1F

ft error in (2k + 1)

A1

Using part (a)

B1 E1

6

8

Dependent on all marks correct

MFP2 (cont) Q 7(a)(i)

Solution

cos5θ + isin 5θ = ( cos θ + isin θ ) Expansion in any form Equate real parts:

Marks 5

cos5θ = cos5 θ – 10cos3 θ sin 2 θ + 5cosθ sin 4 θ

Total

M1 A1 m1 A1

Comments

Attempt to expand 3 correct terms Correct simplification AG

Equate imaginary parts: sin 5θ = 5cos 4 θ sin θ – 10cos 2 θ sin 3 θ + sin 5 θ

(ii)

sin 5θ cos 5θ Division by cos5 θ or by cos 4 θ tan 5θ =

tan 5θ =

(b)

(c)

A1

5

M1

CAO Used

m1

tan θ ( 5 – 10 tan 2 θ + tan 4 θ ) 1 –10 tan 2 θ + 5 tan 4 θ

π  tan 5θ = 0 5 π ∴ tan satisfies t 4 –10t 2 + 5 = 0 5 kπ k = 2, 3, 4 Other roots tan 5

θ=

A1

AG

M1

Or for tan 4 θ – 10 tan 2 θ + 5 = 0

A1

Or for tan 5θ = 0

B1

Product of roots = 5 π 4π tan = – tan 5 5 π 2π tan 2 tan 2 =5 5 5 π 2π tan tan =+ 5 5 5 – sign rejected with reason

3

3

OE

M1 Or tan

B1

2π 3π = – tan 5 5

A1 A1 E1

5 Alternative (c) Use of quadratic formula t2 = 5 ± 2 5

M1 A1

t = ± 5± 2 5 B1 Correct selection of +ve values E1 Multiplied together to get 5 A1 Total TOTAL

16 75



Scaled mark unit grade boundaries - June 2011 exams A-level

Code

Title

Max. Scaled Mark

Scaled Mark Grade Boundaries and A* Conversion Points A* A B C D E

MS1B MD02 MFP2 MM2B MPC2 MS2B XMCA2 MFP3 MM03 MPC3 MS03 MFP4 MM04 MPC4 MS04 MM05

GCE MATHEMATICS UNIT S1B GCE MATHEMATICS UNIT D02 GCE MATHEMATICS UNIT FP2 GCE MATHEMATICS UNIT M2B GCE MATHEMATICS UNIT PC2 GCE MATHEMATICS UNIT S2B GCE MATHEMATICS UNIT XMCA2 GCE MATHEMATICS UNIT FP3 GCE MATHEMATICS UNIT M03 GCE MATHEMATICS UNIT PC3 GCE MATHEMATICS UNIT S03 GCE MATHEMATICS UNIT FP4 GCE MATHEMATICS UNIT M04 GCE MATHEMATICS UNIT PC4 GCE MATHEMATICS UNIT S04 GCE MATHEMATICS UNIT M05

75 75 75 75 75 75 125 75 75 75 75 75 75 75 75 75

69 62 68 62 88 69 67 68 68 68 63 58 67 62

59 64 55 62 54 54 76 64 59 59 62 61 57 51 60 55

52 56 48 55 47 46 66 55 51 52 54 53 51 46 52 48

46 49 41 48 41 38 57 46 43 46 46 46 45 41 44 41

40 42 34 41 35 30 48 38 36 40 39 39 39 36 37 34

34 35 28 34 29 23 39 30 29 34 32 32 33 31 30 28

MEST1 MEST2 MEST3 MEST4

GCE MEDIA STUDIES UNIT 1 GCE MEDIA STUDIES UNIT 2 GCE MEDIA STUDIES UNIT 3 GCE MEDIA STUDIES UNIT 4

80 80 80 80

70 74

55 63 61 68

47 54 50 56

40 45 39 45

33 36 28 34

26 28 18 23

MHEB1 MHEB2

GCE MODERN HEBREW UNIT 1 GCE MODERN HEBREW UNIT 2

100 100

80

61 71

54 62

47 54

40 46

34 38

MUSC1 MUS2A MUS2B MUS2C

GCE MUSIC UNIT 1 GCE MUSIC UNIT 2A GCE MUSIC UNIT 2B GCE MUSIC UNIT 2C

80 60 60 60

-

57 45 49 49

51 40 43 44

45 35 37 39

39 30 32 34

34 26 27 29