4754A June 2007

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INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces provided on the answer booklet. Answer all the questions. You are permitted to use a graphical calculator in this paper. Final answers should be given to a degree of accuracy appropriate to the context. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 72. ADVICE TO CANDIDATES Read each question carefully and make sure you know what you have to do before starting your answer. You are advised that an answer may receive no marks unless you show sufficient detail of the working to indicate that a correct method is being used. NOTE This paper will be followed by Paper B: Comprehension. This document consists of 6 printed pages and 2 blank pages. HN/5 © OCR 2007 [T/102/2653] OCR is an exempt Charity [Turn over ADVANCED GCE UNIT 4754(A)/01 MATHEMATICS (MEI) Applications of Advanced Mathematics (C4) Paper A THURSDAY 14 JUNE 2007 Afternoon Time: 1 hour 30 minutes Additional materials: Answer booklet (8 pages) Graph paper MEI Examination Formulae and Tables (MF2)

Transcript of 4754A June 2007

INSTRUCTIONS TO CANDIDATES

• Write your name, centre number and candidate number in the spaces provided on the answer booklet.

• Answer all the questions.

• You are permitted to use a graphical calculator in this paper.

• Final answers should be given to a degree of accuracy appropriate to the context.

INFORMATION FOR CANDIDATES

• The number of marks is given in brackets [ ] at the end of each question or part question.

• The total number of marks for this paper is 72.

ADVICE TO CANDIDATES

• Read each question carefully and make sure you know what you have to do before starting youranswer.

• You are advised that an answer may receive no marks unless you show sufficient detail of theworking to indicate that a correct method is being used.

NOTE

• This paper will be followed by Paper B: Comprehension.

This document consists of 6 printed pages and 2 blank pages.

HN/5 © OCR 2007 [T/102/2653] OCR is an exempt Charity [Turn over

ADVANCED GCE UNIT 4754(A)/01MATHEMATICS (MEI)Applications of Advanced Mathematics (C4)

Paper A

THURSDAY 14 JUNE 2007 AfternoonTime: 1 hour 30 minutes

Additional materials:Answer booklet (8 pages)Graph paperMEI Examination Formulae and Tables (MF2)

Section A (36 marks)

1 Express in the form where R and a are constants to be determined,and

Hence solve the equation for [7]

2 Write down normal vectors to the planes and

Hence show that these planes are perpendicular to each other. [4]

3 Fig. 3 shows the curve and part of the line

Fig. 3

The shaded region is rotated through 360° about the y-axis.

(i) Show that the volume of the solid of revolution formed is given by [3]

(ii) Evaluate this, leaving your answer in an exact form. [3]

4 A curve is defined by parametric equations

Show that the cartesian equation of the curve is [4]

5 Verify that the point lies on both the lines

Find the acute angle between the lines. [7]

r r=-

Ê

ËÁÁ

ˆ

¯˜˜

+-Ê

ËÁÁ

ˆ

¯˜˜

ËÁÁ

ˆ

¯˜˜

+-

Ê

ËÁÁ

ˆ

¯˜˜

121

123

063

102

l mand .

(�1, 6, 5)

y �3 � 2x

2 � x.

x �1t � 1, y �

2 � t

1 � t.

p e d2

0

2y yÛ

ıÙ.

O

2

y

x

y � 2.y � ln x

x � 2y � z � 5.2x � 3y � 4z � 10

0° � q � 360°.sin q � 3 cos q � 1

0° � a � 90°.R sin (q � a),sin q � 3 cos q

2

© OCR 2007 4754A/01 June 07

6 Two students are trying to evaluate the integral

Sarah uses the trapezium rule with 2 strips, and starts by constructing the following table.

(i) Complete the calculation, giving your answer to 3 significant figures. [2]

Anish uses a binomial approximation for and then integrates this.

(ii) Show that, provided is suitably small, [3]

(iii) Use this result to evaluate approximately, giving your answer to 3 significant

figures. [3]

11

2

+ÛıÙ

-e dx x

1 112 1

218

2+( ) ª + -- - -e e ex x x .e�x

1 + -e x

x 1 1.5 2

1.1696 1.1060 1.06551 + e- x

11

2

+ÛıÙ

-e dx x.

3

© OCR 2007 4754A/01 June 07 [Turn over

Section B (36 marks)

7 Data suggest that the number of cases of infection from a particular disease tends to oscillatebetween two values over a period of approximately 6 months.

(a) Suppose that the number of cases, P thousand, after time t months is modelled by the equation

Thus, when

(i) By considering the greatest and least values of , write down the greatest and leastvalues of P predicted by this model. [2]

(ii) Verify that P satisfies the differential equation [5]

(b) An alternative model is proposed, with differential equation

As before,

(i) Express in partial fractions. [4]

(ii) Solve the differential equation (*) to show that

[5]

This equation can be rearranged to give

(iii) Find the greatest and least values of P predicted by this model. [4]

Pt

=-

1

212e sin

.

ln sin .2 1 1

2PP

t-Ê

ˈ¯ =

1P(2P�1)

P � 1 when t � 0.

dP

dt� 1

2 (2P 2 � P) cos t. (*)

dP

dt� 1

2 P 2 cos t.

sin t

t � 0, P � 1.P �2

2 � sin t.

4

© OCR 2007 4754A/01 June 07

8

Fig. 8

In a theme park ride, a capsule C moves in a vertical plane (see Fig. 8). With respect to the axesshown, the path of C is modelled by the parametric equations

where x and y are in metres.

(i) Show that

Verify that when Hence find the exact coordinates of the highest point A on

the path of C. [6]

(ii) Express in terms of Hence show that

[4]

(iii) Using this result, or otherwise, find the greatest and least distances of C from O. [2]

You are given that, at the point B on the path vertically above O,

(iv) Using this result, and the result in part (ii), find the distance OB. Give your answer to 3 significant figures. [4]

2 cos 2q � 2 cos q � 1 � 0.

x 2 � y 2 � 125 � 100 cos q.

q.x 2 � y 2

q � 13 p.

dy

dx� 0

dy

dx� �

cos q � cos 2qsin q � sin 2q

.

x � 10 cos q � 5 cos 2q, y � 10 sin q � 5 sin 2q , (0 � q � 2p),

x

y

C(x, y)

O

B A

5

© OCR 2007 4754A/01 June 07

4754 Mark Scheme June 2007

Section A

1 sin θ − 3 cos θ = R sin(θ − α) = R(sin θ cos α − cos θ sin α) ⇒ R cos α = 1 , R sin α = 3 ⇒ R2 = 12 + 32 = 10 ⇒ R = √10 tan α = 3 ⇒ α = 71.57° √10 sin(θ − 71.57°) = 1 ⇒ θ − 71.57° = sin (1/√10) 1−

θ − 71.57°= 18.43°, 161.57° ⇒ θ = 90° , 233.1°

M1 B1 M1 A1 M1

B1 A1 [7]

equating correct pairs oe ft www cao (71.6°or better) oe ft R, α www and no others in range (MR-1 for radians)

2 Normal vectors are and 234

⎛ ⎞⎜ ⎟⎜ ⎟⎜ ⎟⎝ ⎠

12

1

⎛ ⎞⎜ ⎟−⎜ ⎟⎜ ⎟⎝ ⎠

⇒ 2 13 . 2 2 6 4 04 1

⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟− = − + =⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

⇒ planes are perpendicular.

B1 B1 M1 E1 [4]

3 (i) y = ln x ⇒ x = e y

⇒ 2 2

0V xπ= ∫ dy

= 2 22 2

0 0( ) *y ye dy e dyπ π=∫ ∫

B1 M1 E1 [3]

(ii) 2

2 2 2

00

12

y ye dy eπ π ⎡ ⎤= ⎢ ⎥⎣ ⎦∫

= ½ π(e4 – 1)

B1 M1 A1 [3]

½ e2y

substituting limits in kπe 2 y

or equivalent, but must be exact and evaluate e0 as 1.

4 1 11 1x xt t

= − ⇒ = +

⇒ 11

tx

=+

⇒ 12 2 2 1 2 311 1 1 21

1

x xxyx x

x

+ + + ++= = =+ + ++

+

M1 A1 M1 E1

Solving for t in terms of x or y Subst their t which must include a fraction, clearing subsidiary fractions/ changing the subject oe www

or 2 233 212 2

tx t

txt

−++

=−+ +

= 3 2 22 1t tt t+ −+ −

= 21

tt++

= y

M1 A1 M1 E1 [4]

substituting for x or y in terms of t

clearing subsidiary fractions/changing the subject

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4754 Mark Scheme June 2007

5 ⇒ 1 12 2

1 3λ

−⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟= +⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟−⎝ ⎠ ⎝ ⎠

r12 2

1 3

xyz

λλλ

−⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟= +⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟− +⎝ ⎠ ⎝ ⎠

When x = −1, 1 − λ = −1, ⇒ λ = 2 ⇒ y = 2 + 2λ = 6, z = −1 + 3λ = 5 ⇒ point lies on first line

⇒ 0 16 03 2

μ⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟= +⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟−⎝ ⎠ ⎝ ⎠

r 63 2

xyz

μ

μ

⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟=⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟−⎝ ⎠ ⎝ ⎠

When x = −1, μ = −1, ⇒ y = 6, z = 3 − 2μ = 5 ⇒ point lies on second line

Angle between and is θ, where 1

23

−⎛ ⎞⎜ ⎟⎜ ⎟⎜ ⎟⎝ ⎠

10

2

⎛ ⎞⎜ ⎟⎜ ⎟⎜ ⎟−⎝ ⎠

1 1 2 0 3 2cos14. 5

θ − × + × + × −=

= 770

⇒ θ = 146.8° ⇒ acute angle is 33.2°

M1 E1

E1 M1

M1 A1 A1cao [7]

Finding λ or μ checking other two coordinates checking other two co-ordinates Finding angle between correct vectors use of formula

770

±

Final answer must be acute angle

6(i) (1.1696 1.06550.5[ 1.1060]2

A +≈ +

= 1.11 (3 s.f.)

M1

A1 cao [2]

Correct expression for trapezium rule

(ii) 1/ 2 2

1 1.1 2 2(1 ) 1 ( ) ...2 2!

x x xe e e− − −−

+ = + + +

21 112 8

x xe e− −≈ + − *

M1 A1 E1 [3]

Binomial expansion with p = ½ Correct coeffs

(iii) I = 2 2

1

1 1(1 )2 8

x xe e− −+ −∫

dx

= 2

2

1

1 12 16

x xx e e− −⎡ ⎤− +⎢ ⎥⎣ ⎦

= 2 4 11 1 1 1(2 ) (1 )2 16 2 16

e e e e− − −− + − − + 2−

= 1.9335 − 0.8245 = 1.11 (3 s.f.)

M1 A1 A1 [3]

integration substituting limits into correct expression

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4754 Mark Scheme June 2007

Section B

7 (a) (i) Pmax = 2

2 1− = 2

Pmin = 22 1+

= 2/3.

B1 B1 [2]

(ii) 12 2(2 sin )2 sin

P tt

−= = −−

⇒ 22(2 sin ) . cosdP t tdt

−= − − −

= 2

2cos(2 sin )

tt−

22

1 1 4cos cos2 2 (2 sin )

P tt

=−

t

= 2

2cos(2 sin )

tt−

= dPdt

M1 B1 A1 DM1 E1 [5]

chain rule −1(…)−2 soi (or quotient rule M1,numerator A1,denominator A1) attempt to verify or by integration as in (b)(ii)

(b)(i) 1

(2 1) 2 1A B

P P P P= +

− −

= (2 1)(2 1)

A P BP P

− +−

P

⇒ 1 = A(2P − 1) + BP P = 0 ⇒ 1 = −A ⇒ A = −1 P = ½ ⇒ 1 = A.0 + ½ B ⇒ B = 2 So 1 1

(2 1) 2 1P P P P= − +

− −2

M1 M1

A1 A1 [4]

correct partial fractions substituting values, equating coeffs or cover up rule A = −1 B = 2

(ii) 21 (2 )cos2

dP P P tdt

= −

⇒ 2

1 1 cos2 2

dP tdtP P

=−∫ ∫

⇒ 2 1 1( ) co2 1 2

dP tdtsP P

− =−∫ ∫

⇒ ln(2P − 1) − ln P = ½ sin t + c When t = 0, P = 1 ⇒ ln 1 − ln 1 = ½ sin 0 + c ⇒ c = 0 ⇒ 2 1 1ln( ) sin

2P tP−

= *

M1 A1 A1 B1 E1 [5]

separating variables ln(2P − 1) − ln P ft their A,B from (i) ½ sin t finding constant = 0

(iii) Pmax =

1/ 2

12 e−

= 2.847

Pmin = 1/ 2

12 e−−

= 0.718

M1A1 M1A1 [4]

www www

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4754 Mark Scheme June 2007

8 (i) 10cos 10cos 210sin 10sin 2

dydx

θ θθ θ+

=− −

= cos cos 2sin sin 2

θ θθ θ

+−

+ *

When θ = π/3, dydx

= cos / 3 cos 2 / 3sin / 3 sin 2 / 3

π ππ π

+−

+

= 0 as cos π/3 = ½ , cos 2π/3 = −½ At A x = 10 cos π/3 + 5 cos 2π/3 = 2½ y = 10 sin π/3 + 5 sin 2π/3 = 15√3/2

M1 E1 B1 M1 A1 A1 [6]

dy/dθ ÷dx/dθ or solving cosθ+cos2θ=0 substituting π/3 into x or y 2½ 15√3/2 (condone 13 or better)

(ii) 2 2 2(10cos 5cos 2 ) (10sin 5sin 2 )x y 2θ θ θ+ = + + + θ

θθ

= 2 2100 cos 100 cos cos 2 25cos 2θ θ θ+ + 2 2100sin 100sin sin 2 25sin 2θ θ θ+ + + = 100 + 100cos(2θ − θ) + 25 = 125 + 100cos θ *

B1 M1 DM1 E1 [4]

expanding cos 2θ cos θ + sin 2θ sin θ = cos(2θ − θ) or substituting for sin 2θ and cos 2θ

(iii) Max 125 100+ = 15 min 125 100− = 5

B1 B1 [2]

(iv) 2cos2 θ +2cos θ − 1 = 0

cos θ = 2 12 2 2 34 4

− ± − ±=

At B, cos θ = 1 32

− +

OB2 = 125 + 50(−1 + √3) = 75 + 50√3 = 161.6… ⇒ OB = √161.6… = 12.7 (m)

M1 A1 M1 A1 [4]

quadratic formula or θ=68.53° or 1.20radians, correct root selected or OB=10sinθ+5sin2θ ft their θ/cosθ oe cao

17