9ma0/02: pure mathematics paper 2 mark scheme · b1: substitutes ! into ! to give awrt 7.962 and an...

9MA0/02: Pure Mathematics Paper 2 Mark scheme

Question Scheme Marks AOs

1M1 1.1a

A1 1.1b

dM1 3.1a

A1 1.1b

(4)

1

AltM1 1.1a

A1 1.1b

dM1 3.1a

A1 1.1b

(4)

(4 marks)

Question 1 Notes:

M1:

A1:

dM1:

A1:

length of major arc ! { }7.5(4.8) 36= =

!2 21 225(4.8) 135 7.5 o.e.

2 4r r r= ⇒ = ⇒ =

Uses a correct equation ! to obtain a radius of 7.521e.g. (4.8) 135

2r⎛ ⎞=⎜ ⎟

⎝ ⎠

! { }15 36 15, 36a bπ= − = = −

!2 21 225(4.8) 135 7.5 o.e.

2 4r r r= ⇒ = ⇒ =

Correct exact answer in its simplest form, e.g. !15 36 or 36 15π π− − +

Applies formula for the area of a sector with ! i.e. ! with !

Note: Allow M1 for considering ratios. E.g. !

4.8;θ =21

2r θ 4.8θ =

2

135 4.82rπ π

=

! 21 (4.8)

2r

! { }15 36 15, 36a bπ= − = = −

length of minor arc ! 2 (7.5) 36π= −

! 21 (4.8)

2r

length of minor arc ! 7.5(2 4.8)π= −

Depends on the previous M mark. A complete process for finding the length of the minor arc AB, by either

• ! • !

(their ) (2 4.8)r π× −

2 (their ) (their )(4.8)r rπ −

A level Mathematics specimen papers - Paper 2 Pure Mathematics mark scheme !1


2(a)

M1 1.1b

M1 1.1b

A1* 2.1

(3)

(b)(i)

B1 2.3

(b)(ii)B1 2.4

(2)

(5 marks)

Question 2 Notes:

(a)(i)

M1: See scheme

M1:

A1*:

(a)(ii)

B1: See scheme

(b)(i)

B1: See scheme

(b)(ii)

!2 2 41 11 4 1 3 1

2 4θ θ θ⎛ ⎞ ⎛ ⎞= + − + − +⎜ ⎟ ⎜ ⎟

⎝ ⎠ ⎝ ⎠

Substitutes

into and attempts to apply

Note: It is not a requirement for this mark to write or refer to the term in !

21cos 1

2θ θ≈ − 21 4cos 3cosθ θ+ +

2211

2θ⎛ ⎞−⎜ ⎟

⎝ ⎠

4θ

!

22 2 21 1

1 4cos 3cos 1 4 1 3 12 2

θ θ θ θ⎛ ⎞ ⎛ ⎞+ + ≈ + − + −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

! , so ! gives a good approximation.

258 5 awrt 7.962180π⎛ ⎞− =⎜ ⎟

⎝ ⎠ 5θ = °

Attempts to substitute

into either 21

cos 12

θ θ≈ − 21 4cos or 3cosθ θ+

E.g. • Adele is working in degrees and not radians

• Adele should substitute ! and not ! into the approximation

5180π

θ = 5θ =

! *28 5θ= −

!2 2 431 4 2 3 3

4θ θ θ= + − + − +

Correct proof with no errors seen in working.

Note: It is not a requirement for this mark to write or refer to the term in !4θ


B1:Substitutes ! into ! to give awrt 7.962 and an appropriate conclusion.

5or

180 36π π

θ = 28 5θ−



3 (a) B1 3.3

(1)

(b)M1 3.4

A1 1.1b

(2)

(c)

B1 3.5a

(1)

(4 marks)

Question 3 Notes:

(a)

B1:

(b)

M1:

Note: Later working can imply this mark.

A1 Obtains 11.9 (minutes) with no errors in manipulation seen.

(c)

B1 See scheme

Applies ! and their value of A to the model and rearranges to make ! the subject.60θ = 0.03e t−

! { } 0.030, 75 75 25 50 25 50e tt A Aθ θ −= = ⇒ = + ⇒ = ⇒ = +

! minutes (1 dp)

ln(0.7) 11.8891648 11.90.03

t = = =−

!{ } 0.03 0.03 60 2560 60 25 "50"e e

"50"t tθ − − −

= ⇒ ⇒ = + ⇒ =

A valid evaluation of the model, which relates to the large values of t. E.g.

• As ! then the model is not true for large values of t

• ! does not have any solutions and so the model predicts that tea in the room will never be ! So the model does not work for large values of t

• t = 120 θ = 25 + 50e −0.03(120) = 26.36… which is not approximately equal to 20.3, so the model is not true for large values of t

20.3 25<

0.03 20.3 25e 0.094"50"

t− −= = −

20.3 C.°

Applies ! to give the complete model !0, 75t θ= = 0.0325 50e tθ −= +



4(a)Correct graph in

quadrant 1 and quadrant 2 with V on the x-axis

B1 1.1b

B1 1.1b

(2)

(b)

M1 1.1b

A1 1.1b

(2)

(c)

M1 3.1a

A1 2.5

(2)

(6 marks)

!52 52

x x− > −

States ! and !

or ! marked in the correct position on the xaxis

and 5 marked in the correct position on the y-axis

(0, 5)5 , 02

⎛ ⎞⎜ ⎟⎝ ⎠

52

{critical values are ! } ! 6, 1x = − ⇒ 1 or 6x x< − >

! and !2 5 7 ...x x− = ⇒ = (2 5) 7 ...x x− − = ⇒ =

! 2 5 7x − >

Hence using set notation, e.g.

• !

• !

• !

5 5: :2 2

x x x x⎧ ⎫ ⎧ ⎫< >⎨ ⎬ ⎨ ⎬⎩ ⎭ ⎩ ⎭

!

5,2

x x⎧ ⎫∈ ≠⎨ ⎬⎩ ⎭!

52

⎧ ⎫− ⎨ ⎬⎩ ⎭

!

E.g.

• Solves ! to give !

and solves ! to also give !

• Sketches graphs of ! and ! .

Indicates that these graphs meet at the point !

52 52

x x− = −52

x =

5(2 5)2

x x− − = −52

x =

2 5y x= −52

y x= −

5 , 02

⎛ ⎞⎜ ⎟⎝ ⎠


Question 4 Notes:

(a)

B1: See scheme

B1: See scheme

(b)

M1: See scheme

A1:

(c)

M1:

A1: See scheme. Note: Final answer must be expressed using set notation.

Correct answer, e.g. • !

• !

• !

1 or 6x x< − >

1 6x x< − >!

{ } { }: 1 : 6x x x x< − >!

A complete process of finding that ! and ! meet at only one point. This can be achieved either algebraically or graphically.

2 5y x= −52

y x= −



5

M1 3.1a

A1 1.1b

dM1 2.1

B1 1.1b

A1 1.1b

(5)

5

Alt 1M1 3.1a

A1 1.1b

dM1 2.1

B1 1.1b

A1 1.1b

(5)

5

Alt 2

M1 3.1a

A1 1.1b

dM1 2.1

B1 1.1b

!

22 21 22 ( 2 ) 5 ( 4 4 ) 5

3 9y k y y k ky y⎛ ⎞= + − ⇒ = + + −⎜ ⎟

⎝ ⎠

o.e.16916

k <

!{ }2 2" 4 " 0 3 4( 4)(10 ) 0b ac k− > ⇒ − − − >

! intersects ! at two distinct points3 2x y k− = 22 5y x= −

o.e.16916

k <

!{ }2 2 2" 4 " 0 (8 9) 4(8)(2 45) 0b ac k k− > ⇒ − − − >

Eliminate y and forms quadratic equation = 0 or quadratic expression

! { }0=

Critical value obtained of !16916

!{ }2 23 2(2 5) 4 3 10 0x x k x x k− − = ⇒ − + + − =


! . So !

d 3 3 34 , 4d 2 2 8ly

x m x xx= = ⇒ = ⇒ =

23 1512 58 32

y ⎛ ⎞= − = −⎜ ⎟⎝ ⎠


!2 28 (8 9) 2 45 0y k y k+ − + − =

!9 16(10 ) 0 169 16 0k k+ − > ⇒ − >

Eliminate y and forms quadratic equation = 0 or quadratic expression

! { }0=

!3 1513 2 ...8 32

k k⎛ ⎞ ⎛ ⎞= − − ⇒ =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

!2 264 144 81 64 1440 0 144 1521 0k k k k− + − + > ⇒ − + >


A1 1.1b

(5)

(5 marks)

o.e.16916

k <


Question 5 Notes:

M1:

A1:

dM1:

B1: See scheme

A1:

Alt 2

M1:

A1:

dM1:

B1: See scheme

A1:

Correct algebra leading to ! 3 151,8 32

x y= = −

Complete strategy of eliminating x or y and manipulating the resulting equation to form a

quadratic equation = 0 or a quadratic expression !{ }0=

Complete strategy of using differentiation to find the values of x and y where ! is a

tangent to !

3 2x y k− =22 5y x= −

Correct answer, e.g.

• !

• !

16916

k <

169:16

k k⎧ ⎫<⎨ ⎬⎩ ⎭

Deduces correct answer, e.g.

• !

• !

16916

k <

169:16

k k⎧ ⎫<⎨ ⎬⎩ ⎭

Depends on the previous M mark.

Interprets ! intersecting ! at two distinct points by applying

! to their quadratic equation or one-sided quadratic.

3 2x y k− = 22 5y x= −2" 4 " 0b ac− >

Depends on the previous M mark.

Full method of substituting their ! into l and attempting to find the value for k.3 151,8 32

x y= = −

Correct algebra leading to either

• ! or !

or a one-sided quadratic of either ! or !

• !

or a one-sided quadratic of e.g. !

24 3 10 0x x k− + + − = 24 3 10 0x x k− − + =

24 3 10x x k− + + − 24 3 10x x k− − +

2 28 (8 9) 2 45 0y k y k+ − + − =

2 28 (8 9) 2 45y k y k+ − + −



6(a)

x coordinates are 1 and 8 B1 1.1b

(1)

(b) M1 3.1a

M1 1.1b

A1 1.1b

A1* 2.1

(4)

(c) M1 1.1b

A1 2.4

(2)

(d)(i) B1 1.1b

(d)(ii) B1 2.2a

(2)

(9 marks)

Crosses x-axis ! f ( ) 0 (8 ) ln 0x x x⇒ = ⇒ − =

! f ( ) (8 ) ln , 0x x x x= − >

!8f ( ) ln x

x xx−

ʹ = − +

!{ }5 3.5340x =

!

(8 ) lnd d 11d d

u x v xu vx x x

= − =⎧ ⎫⎪ ⎪⎨ ⎬

= − =⎪ ⎪⎩ ⎭

! and !

Sign change and as ! is continuous, the x coordinate of Q lies between ! and !

f (3.5) 0.032951317...ʹ = f (3.6) 0.058711623...ʹ = −

f ( )xʹ

3.5x = 3.6x =

Complete strategy of setting ! and rearranges to make ! f ( ) 0xʹ = ...x =

Evaluates both ! and !f (3.5)ʹ f (3.6)ʹ

!

! *

8 8ln 0 ln 1 0xx x

x x−

− + = ⇒ − + − =

8 81 ln1 ln

x xx x

⇒ = + ⇒ =+

! (2 dp){ }3.54Qx =


Question 6 Notes:

(a)

B1: Either • 1 and 8 • on Figure 2, marks 1 next to A and 8 next to B

(b)

M1:

M1:

A1:

A1*: Correct proof with no errors seen in working.

(c)

M1:

A1:

(d)(i)

B1: See scheme

(d)(ii)

B1: Deduces (e.g. by the use of further iterations) that the x coordinate of Q is 3.54 accurate to 2 dp

! or equivalent Note: This mark can be recovered for work in part (c)

8(8 ) ln ln ,xx x xx−

− → − +

Evaluates both ! and !f (3.5)ʹ f (3.6)ʹ

Applies ! , where ! Note: This mark can be recovered for work in part (c)

vu uvʹ ʹ+ 8 , lnu x v x= − =

Note: !3.5 3.55119 3.52845 3.53848 3.53404 3.53600 3.53514 ( 3.535518...)→ → → → → → →

Recognises that Q is a stationary point (and not a root) and applies a complete strategy of setting

! and rearranges to make !f ( ) 0xʹ = ...x =

! and ! or ! (truncated) and a correct conclusion

f (3.5) awrt 0.03ʹ = f (3.6) awrt 0.06ʹ = − f (3.6) 0.05ʹ = −



7(a)B1 3.3

M1 1.1b

A1 1.1b

A1 * 2.1

(4)

(b)

M1 2.1

A1 1.1b

A1 1.1b

(3)

(c)

B1 2.2a

B1 1.1b

(2)

(d)(i)B1 3.4

(d)(ii) E.g. • Rate of increase per hour of the area of bacterial culture • The area of bacterial culture increases by “15%” each hour

B1 3.4

(2)

(e) The model predicts that the area of the bacteria culture will increase indefinitely, but the size of the circular dish will be a constraint on this area.

B1 3.5b

(1)

(12 marks)

vertical intercept ! 3.95ln 3.95 e 51.935 52 (2 sf )a a= = ⇒ = = =

! d dd dp pp k pt t∝ ⇒ =

! gradient 0.14k= =

Initial area (i.e. ! ) of bacterial culture that was first placed onto the circular dish.

2"52" mm

! and evidence of understanding that either

• !

• vertical intercept ! or !

e ln lnktp a p a kt= ⇒ = +

gradient or " "k M k= =

ln a= " " lnC a=

! which can be implied by !1.15b = 52(1.15)tp =

! ! *ln p kt c= + ⇒ e e e ekt c kt c ktp p a+= = ⇒ =

e.g.

• !

• !

e (e ) ,kt k t tp a p a ab= ⇒ = =

0.14 0.1452e 52(e )t tp p= ⇒ =

! { }ln p kt c= +

!1 d dp k tp

=∫ ∫


Question 7 Notes:

(a)

B1:

M1: Correct method of separating the variables p and t in their differential equation

A1:

A1*: Correct proof with no errors seen in working.

(b)

M1: See scheme

A1:

A1:

(c)

B1:

B1: See scheme

(d)(i)

B1: See scheme

(d)(ii)

B1: See scheme

(e)

B1: Gives a correct long-term limitation of the model for p. (See scheme).

Correctly finds ! 52a =

Translates the scientist’s statement regarding proportionality into a differential equation, which

involves a constant of proportionality. e.g. !d dd dp pp k pt t∝ ⇒ =

Correctly finds ! 0.14k =

! with or without a constant of integrationln ,p kt=

Uses algebra to correctly deduce either

• ! from !

• ! from !

tp ab= ektp a="0.14""52"(e )tp = "0.14""52"e tp =



8(a)

M1 1.1b

A1 1.1b

M1 3.1a

dM1 3.4

A1 1.1b

(5)

(b)M1 3.4

A1 1.1b

(2)

(7 marks)

Question 8 Notes:

(a)

M1:

A1:

M1:

M1: Depends on the previous M mark.

A1: Obtains the correct answer 0.4

(b)

! -1d 0.5 (cms )

dht=

Differentiates V with respect to h to give !2 , 0, 0h hα β α β± ± ≠ ≠

!2

d 300d 50 (20) (20)ht

ππ π

=−

! , !d 160dVt

π= 2 2 31 1(75 ) 253 3

V h h h hπ π π= − = −

2d 50

dV h hh

π π= −

Substitutes ! into their model for ! which is in the form !10h =ddht

160dtheirdVh

π⎛ ⎞⎜ ⎟⎝ ⎠

!-1d 0.4 (cms )

dht=

When ! !10,h = 2

d d d 160 160d d d 50 (10) (10) 400h V Vt t h

π ππ π π

⎧ ⎫ ⎧ ⎫= ÷ ⇒ =⎨ ⎬ ⎨ ⎬−⎩ ⎭ ⎩ ⎭

Attempts to solve the problem by applying a complete method of !

d dtheir 160d dV hh t

π⎛ ⎞× =⎜ ⎟⎝ ⎠

! !d d dd d dV h Vh t t

⎧ ⎫× = ⇒⎨ ⎬⎩ ⎭

( )2 d50 160dhh ht

π π π− =

!250 h hπ π−


M1:

A1: Obtains the correct answer 0.5

Realises that rate for of ! for ! has no effect when the rate is increased to

! for ! and so substitutes ! into their model for ! which is in the

form !

3 1160 cm sπ − 0 12h„ „

3 1300 cm sπ − 12 24h< „ 20h =ddht

300dtheirdVh

π⎛ ⎞⎜ ⎟⎝ ⎠



9(a)M1 1.1b

A1 2.1

(2)

(a)

Alt 1M1 1.1b

A1 2.1

(2)

(a)

Alt 2

M1 1.1b

A1 2.1

(2)

(b) Uses Pythagoras in a correct method to find either the radius or diameter of the circle. M1 1.1b

M1 1.1b

A1 1.1b

(3)

(c)M1 3.1a

A1 1.1b

(2)

(d)M1 3.1a

A1 1.1b

(2)

e.g. as ! , then PQ is the diameter of the circle.2PQ AP=

E.g. midpoint PQ !

9 15 8 10,2 2

− + −⎛ ⎞= ⎜ ⎟⎝ ⎠

! and either

• !

• !

{ }2 2( 9 15) (8 10) 900 30PQ = − − + − − = =

{ }2 2(3 9) ( 1 8) 225 15AP = − − + − − = =

{ }2 2(3 15) ( 1 10) 225 15AQ = − + − − − = =

Distance ! or !2 2("15") (10)= −

2 21 (2("15")) (2(10))2

= −

! which is the centre point A, so PQ is the diameter of the circle.

( )3, 1 ,= −

! So ! so PQ is the diameter of the circle.

3 5: .4 4

PQ y x= − +3 53 (3) 14 4

x y= ⇒ = − + = −

!( )( )22 2( 3) ( 1) 225 or 15x y− + + =

!

10 8 3 3: 8 ( 9)15 9 4 4PQm PQ y x− −

= = − ⇒ − = − − −− −

! or !

20ˆsin( )2("15")

ARQ = 1 10ˆ 90 cos"15"

ARQ − ⎛ ⎞= − ⎜ ⎟⎝ ⎠

! (to 0.1 of a degree)ˆ 41.8103... 41.8ARQ = = °

{ }125 5 5= =


(9 marks)


Question 9 Notes:

(a)

M1: Uses a correct method to find the midpoint of the line segment PQ

A1:

(a)

Alt 1

M1: Full attempt to find the equation of the line PQ

A1:

(a)

Alt 2

M1: Attempts to find distance PQ and either one of distance AP or distance AQ

A1:

(b)

M1:

Note: This mark can be implied by just 30 clearly seen as the diameter or 15 clearly seen as the radius (may be seen or implied in their circle equation)

M1:

A1:

(c)

M1:

A1:

(d)

Completes proof by showing that ! lies on PQ and gives a correct conclusion.(3, 1)−

Either • uses Pythagoras correctly in order to find the radius. Must clearly be identified as the

radius. E.g. ! or ! or

or

or • uses Pythagoras correctly in order to find the diameter. Must clearly be identified as the

diameter. E.g. ! or !

( ) ( )2 22 9 3 8 1r = − − + + ( ) ( )2 29 3 8 1r = − − + +

( ) ( )2 22 15 3 10 1r = − + − + ( ) ( )2 215 3 10 1r = − + − +

( ) ( )2 22 15 9 10 8d = + + − − ( ) ( )2 215 9 10 8d = + + − −

! by correct solution only5 5

Attempts to solve the problem by using the circle property “the perpendicular from the centre to a chord bisects the chord” and so applies Pythagoras to write down an expression of the form

! .2 2(their "15") (10)−

Correctly shows either • ! , supported by ! and gives a correct conclusion • ! , supported by ! and gives a correct conclusion

2PQ AP= 30, 15PQ AP= =

2PQ AQ= 30, 15PQ AQ= =

or

or

2 2( 3) ( 1) 225x y− + + =2 2 2( 3) ( 1) 15x y− + + = 2 26 2 215 0x x y y− + + − =

Completes proof by obtaining ! and gives a correct conclusion.(3, 1)−

Writes down a circle equation in the form ! 2 2 2( "3") ( " 1") (their )x y r± + ± − =


M1:

A1: 41.8 by correct solution only

Attempts to solve the problem by e.g. using the circle property “the angle in a semi-circle is a

right angle” and writes down either ! or

!

Note: Also allow !

20ˆsin( )2(their "15")

ARQ =

1 10ˆ 90 costheir "15"

ARQ − ⎛ ⎞= − ⎜ ⎟

⎝ ⎠

( )( )( ) ( )( )

22 215 2 5 5 15 5ˆcos( )

32 15 2 5 5ARQ

+ − ⎧ ⎫⎪ ⎪= =⎨ ⎬

⎪ ⎪⎩ ⎭



10 (a)B1 2.2a

(1)

(b)M1 3.1a

A1 1.1b

M1 3.1a

A1 1.1b

M1 1.1b

A1 1.1b

M1 2.2a

A1* 2.1

(8)

(b) Alt 1 M1 3.1a

A1 1.1b

M1 3.1a

A1 1.1b

M1 1.1b

A1 1.1b

!

(3)(2) 6ln3 ln 4 ln 2 ln ln4 4

⎛ ⎞ ⎛ ⎞= − + = =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

!

1 1 d ln( 1) ln( 2)( 1) ( 2)

t t tt t

⎧ ⎫⎛ ⎞− = + − +⎨ ⎬⎜ ⎟+ +⎝ ⎠⎩ ⎭∫

!

d 1 1d dd 1 2xy t tt t t

⎧ ⎫ ⎛ ⎞⎛ ⎞= =⎨ ⎬ ⎜ ⎟⎜ ⎟+ +⎝ ⎠⎝ ⎠⎩ ⎭∫ ∫

!

4ln3

x ⎛ ⎞> ⎜ ⎟⎝ ⎠

!1 1 ( 1)( 1) ( 1)

A B A u Buu u u u

≡ + ⇒ ≡ + ++ +

! [ ]20Area( ) ln( 1) ln( 2) (ln3 ln 4) (ln1 ln 2)R t t= + − + = − − −

! !{ }1, 1 givesA B= =− ⇒1 1

( 1) ( 2)t t−

+ +

Attempts to apply !

d ddxy tt∫

!

1 1 d ln ln( 1)( 1)

u u uu u

⎧ ⎫⎛ ⎞− = − +⎨ ⎬⎜ ⎟+⎝ ⎠⎩ ⎭∫

!

1 1d d1

y x uu u

⎧ ⎫ ⎛ ⎞⎛ ⎞=⎨ ⎬ ⎜ ⎟⎜ ⎟+⎝ ⎠⎝ ⎠⎩ ⎭∫ ∫

! *

3ln2

⎛ ⎞= ⎜ ⎟⎝ ⎠

!

1 1 ( 2) ( 1)( 1)( 2) ( 1) ( 2)

A B A t B tt t t t

≡ + ⇒ ≡ + + ++ + + +

! !{ }1, 1 givesA B= =− ⇒1 1

( 1)u u−

+

Attempts to apply ! ,

with a substitution of !

1 1d d de 2 1 e 1x xy x x x= =− + −∫ ∫ ∫

e 1xu = −


M1 2.2a

A1 * 2.1

(8)

(9 marks)

! [ ]31Area( ) ln ln( 1) (ln3 ln 4) (ln1 ln 2)R u u= − + = − − −

! *

3ln2

⎛ ⎞= ⎜ ⎟⎝ ⎠

!

(3)(2) 6ln3 ln 4 ln 2 ln ln4 4

⎛ ⎞ ⎛ ⎞= − + = =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠



10 (b) Alt 2 M1 3.1a

A1 1.1b

M1 3.1a

A1 1.1b

M1 1.1b

A1 1.1b

M1 2.2a

A1 * 2.1

(8)

!

(3)(2) 6ln3 ln 4 ln 2 ln ln4 4

⎛ ⎞ ⎛ ⎞= − + = =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

Attempts to apply ! ,

with a substitution of !

1 1d d de 2 1 e 1x xy x x x= =− + −∫ ∫ ∫

exv =

! [ ]42Area( ) ln( 1) ln (ln3 ln 4) (ln1 ln 2)R v v= − − = − − −

!

1 1 d ln( 1) ln( 1)

v v vv v

⎧ ⎫⎛ ⎞− = − −⎨ ⎬⎜ ⎟−⎝ ⎠⎩ ⎭∫

! !{ }1, 1 givesA B= =− ⇒1 1

( 1)v v−

−

!1 1 ( 1)

( 1) ( 1)A B Av B v

v v v v≡ + ⇒ ≡ + −

− −

! *

3ln2

⎛ ⎞= ⎜ ⎟⎝ ⎠

!

1 1d d1

y x vv v

⎧ ⎫ ⎛ ⎞⎛ ⎞=⎨ ⎬ ⎜ ⎟⎜ ⎟−⎝ ⎠⎝ ⎠⎩ ⎭∫ ∫


Question 10 Notes:

(a)

B1:

(b)

M1:

A1:

M1:

A1: Correct partial fractions for their method

M1:

A1: Correct integration for their method

M1:

A1*:

Integrates to give either • !

• ! where !

• ! where !

ln( 1) ln( 2)t tα β± + ± +

ln ln( 1) ; , 0,u uα β α β± ± + ≠ e 1xu = −

ln( 1) ln ; , 0,v vα β α β± − ± ≠ exv =

Applies a strategy of attempting to express either ! , ! or ! as partial fractions

1( 1)( 2)t t+ +

1( 1)u u +

1( 1)v v−

Obtains

• ! from a parametric approach

• ! from a Cartesian approach with !

• ! from a Cartesian approach with !

1 1 d1 2

tt t⎛ ⎞⎛ ⎞⎜ ⎟⎜ ⎟+ +⎝ ⎠⎝ ⎠∫1 1 d

1u

u u⎛ ⎞⎛ ⎞⎜ ⎟⎜ ⎟+⎝ ⎠⎝ ⎠∫ e 1xu = −

1 1 d1

vv v⎛ ⎞⎛ ⎞⎜ ⎟⎜ ⎟−⎝ ⎠⎝ ⎠∫ exv =

Correctly shows that the area of R is ! , with no errors seen in their working

3ln2

⎛ ⎞⎜ ⎟⎝ ⎠

Attempts to solve the problem by either • a parametric process or

• a Cartesian process with a substitution of either ! or !e 1xu = − exv =

Either • Parametric approach: Deduces and applies limits of 2 and 0 in t and subtracts the

correct way round

• Cartesian approach: Deduces and applies limits of 3 and 1 in u, where ! and subtracts the correct way round

• Cartesian approach: Deduces and applies limits of 4 and 2 in v, where ! and subtracts the correct way round

e 1,xu = −

e ,xv =

Uses ! with ! to deduce the correct domain, !ln( 2)x t= +23

t > −4ln3

x ⎛ ⎞> ⎜ ⎟⎝ ⎠



11

M1 2.1

A1 1.1b

M1 2.2a

M1 1.1b

A1 2.1

(5)

(5 marks)

Question 11 Notes:

M1: Complete method to find the value of k

A1:

M1:

M1:

A1:

! ! { }3 10 2 4k k− = − ⇒ 6k =

Correctly shows that the sum of the series is ! and makes an appropriate conclusion.2(2 )n

! (5 10) (2 ) (7 14) (5 10) ...k k k k k− − = − − − ⇒ =

Applies ! with their ! and their d.( )2 ( 1)2nnS a n d= + −

2a T≠

Arithmetic sequence, ! 2 3 42 , 5 10, 7 14T k T k T k= = − = −

Uses their value of k to deduce the common difference and the first term ! of the arithmetic series.

2( )T≠

Uses a correct method to find ! 6k =

! which is a square number( ) 2 28 8 8 4 (2 )2n n n n= + − = =

!( )2(4) ( 1)(8)2nnS n= + −

! . So ! { } 2 3 46 12 , 20, 28k T T T= ⇒ = = = 8, 4d a= =



12

M1 3.1a

B1 1.1b

M1 2.2a

A1 1.1b

M1 1.1b

A1 1.1b

B1 2.1

(7)

(7 marks)

Question 12 Notes:

M1: See scheme

B1:

M1:

A1: See scheme

M1:

Applies

d cos0 (e.g. cos 0 or 0 cos 0) ...d siny xx x xx y= = = ⇒ = ⇒ =

!

d dcos sin 0

d dy y

x yx x

⎧ ⎫= − =⎨ ⎬

⎩ ⎭

Uses the information “the tangent to C at the point P is parallel to the x-axis”

to deduce and apply ! and finds ! d 0dyx= ...x =

Complete process to find at least one set of coordinates for P. The process must include evidence of

• differentiating

• setting ! to find !

• substituting ! into ! to find !

d 0dyx= ...x =

...x = sin cos 0.5x y+ = ...y =

Correct differentiated equation. E.g. !d

cos sin 0dy

x yx

− =

! has no solutions, and so there are exactly 2 possible points P.

sin cos 0.5 cos 1.52 2

x y yπ π⎛ ⎞= − ⇒ − + = ⇒ =⎜ ⎟

⎝ ⎠

So in specified range, ! , by cso

2 2( , ) , and ,2 3 2 3

x yπ π π π⎛ ⎞ ⎛ ⎞= −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

!1 2 2

sin cos 0.5 cos or2 2 2 3 3

x y y yπ π π π⎛ ⎞= ⇒ + = ⇒ = − ⇒ = −⎜ ⎟

⎝ ⎠

giving at least one of either

or 2x

π= −

2x

π=

For substituting one of their values from ! into ! and so finds !

d 0dyx= sin cos 0.5x y+ =

..., ...x y= =


A1:

B1: Complete argument to show that there are exactly 2 possible points P.

Selects coordinates for P on C satisfying

and d 0dyx=

3 ,2 2

x yπ π

π π− < − < <„

i.e. finds ! and no other points by correct solution only

2 2, and ,2 3 2 3π π π π⎛ ⎞ ⎛ ⎞−⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠



13(a)

M1 1.2

M1 1.1b

M1 2.1

A1 1.1b

A1* 2.1

(5)

(b)

M1 2.2a

M1 1.1b

A1 1.1b

M1 2.1

A1 1.1b

(5)

(10 marks)

! ; !cosec(4 + 10 ) cot (4 + 10 ) 3θ θ° + ° = 0 180 ,θ < °„

!cosec2 cot 2 cot , 90 ,x x x x n n+ ≡ ≠ ° ∈!

! 102.5θ = °

cos cot *sinx xx

= =

! 2 5 180 ...PVθ θ+ ° = ° + ° ⇒ = °

21 2cos 12sin cos

xx x

+ −=

22cos2sin cos

xx x

=

!2 ... 30 12.5θ θ± = ° ⇒ = °

1 cos2sin 2

xx

+=

!cot (2 ... ) 3θ ± ° =

!1 cos2

cosec2 cot 2sin 2 sin 2

xx x

x x+ = +


Question 13 Notes:

(a)

M1:

M1: Combines into a single fraction with a common denominator

M1:

A1:

A1*: Correct proof with correct notation and no errors seen in working

(b)

M1:

M1:

A1:

M1:

A1: Uses a correct method to obtain ! , with no extra solutions given either inside or outside the required range !

102.5θ = °

0 180θ < °„

Uses ! in a complete method to find the second solution, ! 2 5 180 their PVθ + = + ° ...θ =

Correct algebra leading to ! or equivalent.

22cos2sin cos

xx x

Uses a correct method to obtain ! 12.5θ = °

• !

• ! and !

• ! and ! to the numerator and manipulates to give a one term numerator expression

2cos2 2cos 1x x= −

2cos2 1 2sinx x= − 2 2sin cos 1x x+ =

2 2cos2 cos sinx x x= − 2 2sin cos 1x x+ =

and attempts to solve ! to give ! 2 ... 30θ ± = ° ...θ =

Applies ! to the denominator and applies eithersin 2 2sin cosx x x=

Applies ! or !( )arccot 3 30= °1arctan 303

⎛ ⎞= °⎜ ⎟

⎝ ⎠

Uses the result in part (a) in an attempt to deduce either ! or ! and uses to write down or imply

2 4 10x θ= + 2 ...x θ= +

2 ...x θ= +

cot (2θ ± ...°) = 3

Writes ! and !1

cosec2sin 2

xx

=cos2

cot2sin 2

xx

x=



14 (i)

M1 2.3

A1 2.4

(2)

(ii)

M1 2.1

M1 1.1b

A1 2.2a

M1 2.1

A1 1.1b

A1 2.4

(6)

(8 marks)

! ! ! is divisible by 3 and so q is divisible by 32 23q c⇒ = ⇒

2q

For an explanation or statement to show when the claim ! fails This could be e.g.

• when ! ! or ! is not greater than or equal to !

• when ! ! or ! is not greater than or equal to !

3 2x x…

1,x = −1 13 2<

13

12

0,x < 3 2x x< 3x 2x

So ! where c is an integer

From earlier, !

3 ,p c=

2 2 2 23 (3 ) 3p q c q= ⇒ =

!

! ! is divisible by 3 and so p is divisible by 3

2 23 3p q p q⇒ = ⇒ =

⇒2p

Assume that ! is a rational number

So ! , where p and q integers, ! and the HCF of p and q is 1

3

3 pq

=0,q ≠

As both p and q are both divisible by 3 then the HCF of p and q is not 1 This contradiction implies that

is an irrational number3

followed by an explanation or statement to show when the claim

! is true. This could be e.g. • ! ! or 9 is greater than or equal to 4

• when ! and a correct conclusion. E.g.

• so the claim ! is sometimes true

3 2x x…

2,x = 9 4…

0, 3 2x xx … …

3 2x x…


Question 14 Notes:

(i)

M1: See scheme

A1: See scheme

(ii)

M1:

M1:

A1: Uses a logical argument to prove that p is divisible by 3

M1:

A1: Hence uses a correct argument, in the same way as before, to deduce that q is also divisible by 3

A1:

Note: All the previous 5 marks need to be scored in order to obtain the final A mark.

! in the form ! , where p and q are correctly defined.3pq

Uses the result that p is divisible by 3, (to construct the initial stage of proving that ! is also

divisible by 3), by substituting ! into their expression for !

q

3p c= 2p

Uses a method of proof by contradiction by initially assuming that ! is rational and expresses 3

Completes the argument (as detailed on the scheme) that ! is irrational.3

Writes ! and rearranges to make ! the subject3 p

q= 2p


9ma0/02: pure mathematics paper 2 mark scheme · b1: substitutes ! into ! to give awrt 7.962 and an...

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