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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
¯˜˜
=Ê
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
14
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
15
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
16
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