prelim ext 1 yearly exam 2012 · 2018. 9. 7. · question4$$...
TRANSCRIPT
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THE SCOTS COLLEGE
MATHEMATICS EXTENS ION I
PREL IMINARY YEARLY
17TH SEPTEMBER 2012
GENERAL INSTRUCTIONS
• Reading time – 5 minutes • Working time -‐ 1.5 hours • Write using black or blue pen • Board-‐approved calculators may be
used • Marks may be deducted for careless
or messy working
WEIGHTING
40%
TOTAL MARKS
56
SECTION I (10 MARKS)
• Multiple choice section • Answers to be recorded on the
multiple choice answer sheet provided • Allow about 15 minutes for this
section
SECTION II (46 MARKS)
• Extended response section • Questions 11-‐ 14 • Answers to be recorded in the answer
booklets provided • Each question must be completed in a
new answer booklet. • Clearly label the booklet order if more
than one booklet is used for a question. (E.g. Book 1 of 2 and 2 of 2)
Learning Intentions Marks Allocated Functions 13 Parametrics 11 Further Trigonometry 18 Further Algebra 3 Calculus 5 Circle Geometry 6
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SECTION I MULTIPLE CHOICE QUESTIONS
QUESTION 1
Two lines, y = 2x + 5 and 5x + 6y+3= 0 , intersect on a Cartesian plane. The value of the acute angle between the lines is closest to:
(A) 77°
(B) 283°
(C) 133°
(D) 103°
QUESTION 2
The oblique asymptote of the curve y = x + 1x +3
is
(A) y = x
(B) y = 1x
(C) y = 1x +3
(D) Non-‐existent
QUESTION 3
Find the Cartesian equation to the parametric equations x = cotθ and y = sinθ
(A) x2 + y2 −1= 0
(B) xy2 = cosθ
(C) y+ x2 =1
(D) y2 = 11+ x2
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QUESTION 4
The point X has coordinates (2, -‐4). The point P(1, 5) divides the interval XY internally in the ratio 2 : 3. Find the x-‐coordinates of the point Y
(A) − !!
(B) !!
(C) 75
(D) 85
QUESTION 5
The equation for the chord of contact of tangents from the parabola x2 = 25y from an external point (-‐2, 3) is
(A) −6x = 25 y+ 2( )
(B) 4x = 25 y−3( )
(C) 6x = 25 y− 2( )
(D) −4x = 25 y+3( )
QUESTION 6
Evaluate limx→∞
2x−4 + 5x2 +1x2 + x
(A) Undefined
(B) 0
(C) 5
(D) ∞
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QUESTION 7
Solve x −1 ≤ 2
(A) All real values of x
(B) −3≤ x ≤ 3
(C) x ≤ 3
(D) −1≤ x ≤1
QUESTION 8
sin θ + 45°( ) = − 711 and cos θ + 45°( ) < 0 . If 𝜃 is an acute angle, find the value of tan θ + 45°( )
(A) 7 212
(B) 711
(C) 6 27
(D) Undefined
QUESTION 9
The solution to 1
x − 2> 5 is
(A) 2 < x < 115
(B) 2 ≤ x ≤ 115
(C) x ≥ 115, x ≤ 2
(D) x > 115, x < 2
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QUESTION 10
In the diagram below the chord AD is at right angles to DC and DC is a tangent to the circle.
DIAGRAM NOT TO SCALE
If the length AB is 4 units, BC is 6 units, the diameter of the circle is
(A) 2 10
(B) 4 5
(C) 4 10
(D) None of the above
END OF SECTION I
DC
B
A
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SECTION II ANSWER EACH QUESTION IN A NEW BOOKLET
QUESTION 11 START A NEW QUESTION BOOKLET 14 MARKS
a) Solve x −1 = 3x + 2 2 marks
b) T(4t, 2t2) and W(4w, 2w2) are two points on the parabola x2 = 8y
i. Show that the equation of the normal at T is x + ty = 4t + 2t3
2 marks
ii. TW is a focal chord. Show that tw = −1
2 marks
iii. The equation of the normal at W is x +wy = 4w+ 2w3 (DO NOT SHOW THIS). If the normal at T and the normal at W intersect at Point G, show that the coordinates of G are
−2tw(t +w), 4+ 2(t2 + tw+w2( )
3 marks
iv. Hence find the locus of G 2 marks
c) y = 2−3xx
+ 2
i. State a restriction on x 1 mark
ii. Solve y ≤1 2 marks
QUESTION 12 START A NEW QUESTION BOOKLET 10 MARKS
a) y = 4x − 1x
i. State the x-‐intercepts of the function
1 mark
ii. Find the asymptotes of the function
2 marks
iii. Show that the function has no stationary points 1 mark
iv. Sketch the curve y = 4x − 1x
2 marks
b) 3cos θ( )− sin θ( ) = Rcos θ +β( ) where R > 0 and 0 ≤ β ≤ 90
i. Find the value of R and β
2 marks
ii. Hence solve for θ if 3cos θ( )− sin θ( ) = −1 0 ≤θ ≤ 360 2 marks
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QUESTION 13 START A NEW QUESTION BOOKLET 10 MARKS
a) In the diagram below, OD intersects the chord AC at right angles and
O is the circle centre. Find the value of , giving reasons with your answer DIAGRAM NOT TO SCALE
5 marks
b) A car, F, leaves a carpark at 1pm and travels due south at a speed of 60km/h. Another car, E, heading due east at 80km/h, reaches the same carpark at 2pm.
i. Show that the distance, D, between the cars at any time, t, is
D = 20 25t2 −32t +16( )12
where t is the time from 1pm
2 marks
ii. Hence find the minimum distance between the two cars (You are not required to show the test of the nature of the stationary point)
3 marks
QUESTION 14 ON THE NEXT PAGE
sinθ
C
B
A
D
θ
60°
O
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QUESTION 14 START A NEW QUESTION BOOKLET 12 MARKS
a) 2sinθ cosθ − sin2θ = 0
i. If t = tan θ2!
"#$
%& , show that t = 0 and t =
−1± 52
3 mark
ii. Hence find all values of θ to the nearest degree if 0 0 then the height of Tower
A is restricted to H2 >20
tan20
2 marks
END OF EXAMINATION
Tower A
Tower B
H1H2
A
BM