king david high school linksfield
TRANSCRIPT
KING DAVID HIGH SCHOOL LINKSFIELD
PRELIMINARY EXAMINATION
AUGUST 2020
MATHEMATICS: PAPER II
Time: 3 hours Total: 150 marks
Name:_______________________________ Teacher:_________________ PLEASE READ THE FOLLOWING INSTRUCTIONS CAREFULLY 1. This question paper consists of 30 pages and an information sheet of 2 pages. Please check that your paper is complete. 2. Read the questions carefully. 3. Answer all the questions on the question paper and hand it in at the end of the examination. 4. Four blank pages have been included at the end of the exam paper. If you run out of space, use these pages. Make sure that you indicate this when you make use of this space and number these answers exactly as they are in the paper. 5. Diagrams are not necessarily drawn to scale. 6. You may use an approved non-programmable and non-graphical calculator, unless stated otherwise. Ensure that your calculator is in DEGREE mode. 7. Clearly show ALL calculations, diagrams, etc. that you use in determining your answers. Answers only will NOT necessarily be given full marks. 8. Round off to one decimal place unless stated otherwise. 9. It is in your best interest to write legibly and present your work neatly. 10. DO NOT USE TIPPEX.
Q1 (9) Q2 (12) Q3 (12) Q4 (10) Q5 (10) Q6 (10) Q7 (9) Total
Q8 (8) Q9 (14) Q10 (7) Q11 (14) Q12 (14) Q13 (5) Q14 (8) Q15 (8) %
PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 2 of 30 SECTION A
QUESTION 1
The vertices of ABC are ( )2; 5A , ( )4; 0B − and ( ); 5C a − . 1
1; 22
M
−
is the
midpoint of BC and AD BC⊥ .
(a) Determine the value of a. (1)
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(b) Determine the gradient of BC and hence, the equation of AD. (4)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 3 of 30 (c) Line AQ is parallel to BC and has the equation 2 3 4y qx+ = .
(1) Show that the equation can be written as 3
22
qy x
−= + . (2)
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(2) Hence, calculate the value of q. (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 4 of 30 QUESTION 2
(a) If sin47 k = , determine, in terms of k:
(1) ( )sin 133− (3)
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(2) sin77 (4)
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(b) Prove that: sin2 sin
tancos2 cos 1
x xx
x x
+=
+ + (5)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 5 of 30 QUESTION 3
(a) Use the diagram below to prove the theorem that states the following:
If DE ST in RST then RD RE
DS ET= . (6)
Construction: ________________
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Proof:
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 6 of 30 (b) BC is the diameter of the larger circle and DE is the diameter of the
smaller circle. M is the centre of the smaller circle.
APC is a tangent to the smaller circle at P.
72 , 36PC mm AP mm= = and 45BM mm= .
(1) Prove that MP BA . (3)
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(2) Calculate giving reasons the length of MC. (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 7 of 30 (3) Calculate the radius of the larger circle. (1)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 8 of 30 QUESTION 4
In the sketch ABCD is a cyclic quadrilateral. AD and BC produced meet at E.
CA bisects ˆ ,BAD CD AE⊥ and ˆ 76BAD = .
Calculate, giving reasons, the size of:
(a) 1A (1)
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(b) 1B (2)
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(c) 2B (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 9 of 30
(d) ˆBCD (2)
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(e) E (3)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 10 of 30 QUESTION 5
A cardiologist wanted to test the relationship between resting heart rate and the peak heart rate during exercise. Heart rate is measured in beats per minute (bpm). The following set of data was generated from 12 study participants after they had run on a treadmill at 10 km/h for 10 minutes.
Resting Heart Rate
(x) 48 56 90 65 75 78 80 72 82 68 62 76
Peak Heart Rate
(y) 128 165 180 161 151 161 155 154 175 158 158 158
The scatter plot is drawn below.
(a) Use your calculator to determine the equation of the line of best fit. (2)
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(b) Calculate r, the correlation coefficient. (1)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 11 of 30 (c) Estimate what the heart rate of a person with a resting heart rate of 60 bpm
will be after exercise. (2)
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(d) What can you conclude regarding the relationship between resting heart
rate and the heart rate after exercise? Explain your answer briefly. (3)
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(e) Explain whether it is possible to determine the resting heart rate if the peak
heart rate is 170 bpm. (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 12 of 30 QUESTION 6
(a) In the figure, AB represents a thin metal rod, 130 cm in length, which is
propped up in the corner of a room. OAL is vertical and B is on the
horizontal KOM. ˆ 90KOL = and BC OK⊥ . If ˆ 36,9BOC = and
B is 30 cm from OK.
Calculate:
(1) the distance from B to the corner O, of the room.
Round your answer, correct to the nearest cm. (2)
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(2) the size of ˆOBA . (3)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 13 of 30
(b) PQR is drawn with 20 4PQ x= − , RQ x= and ˆ 60Q = .
(1) Show that the area of 25 3 3PQR x x = − . (2)
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(2) Determine the value of x for which the area of PQR will be maximum.
(3)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 14 of 30 QUESTION 7
In ABC , P is a point on AB. Q and R are points on BC such that AP PB= and BQ QR= . AR cuts PC in T.
(a) Prove RT QP . (2)
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(b) (1) If 5
4
BR
RC= , determine
CT
TP. (3)
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(2) Hence, determine Area CTR
Area CPQ
. (4)
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SECTION A: 72
PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 15 of 30 SECTION B
QUESTION 8
Given: cos 2 and cos2 7p= = , calculate the value(s) of:
(a) p. (5)
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(b) if 0 ;180 . (3)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 16 of 30 QUESTION 9
B is the centre of the circle. CAR is a tangent to the circle at A.
( )1; 26C − .
ˆ ˆ and 20 units.CBA ARQ CA= = =
(a) Determine the length of AB, the radius of the circle. (3) ______________________________________________________________
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(b) Determine the equation of the circle in the form ( ) ( )2 2 2x a y b r− + − = . (2)
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(c) What is the equation of the tangent CR? (4)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 17 of 30 (d) If it is given that the equation of the radius is 4 3 1y x+ = , determine
the coordinates of A. (5) ______________________________________________________________
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 18 of 30 QUESTION 10
A taxi company has 200 taxi cabs. The cumulative frequency curve below shows the fares in hundreds of Rands taken by the cabs on a particular morning.
(a) Use the curve to estimate:
(indicate on the ogive where you read off your answers)
(1) the median fare taken by the company that morning. (1)
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(2) the percentage of taxis in which the fare collected was between
R4 000 and R8 000. (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 19 of 30 (b) The company charges R75 per kilometre travelled. There are no other charges
involved. Use the curve to answer the following questions:
(1) On the morning in questions, 40% of the cabs travel less than
m kilometres. Determine the value of m. (2)
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(2) How many cabs travelled less than 60 km on this morning? (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 20 of 30 QUESTION 11
(a) A circle touches the X-axis at ( )7; 0A and passes through the point ( )2; 1T −
as shown in the diagram below.
Determine the coordinates of the centre of the circle. (5)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 21 of 30 (b) The diagram shows a circle with centre N and equation
2 2 1494 2
4x x y y− + + = . Chord AB of the circle is parallel to the X-axis and
lies below it. The length of AB is 12 units.
(1) Determine the coordinates of N. (3)
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(2) Determine the radius of the circle. (1)
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(3) Calculate the coordinates of A and B. (5)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 22 of 30 QUESTION 12
(a) (1) Show that ( )cos 30 2sinx x+ = can be written as 3 cos 5sinx x= . (4)
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(2) Hence, or otherwise solve for x if ( )cos 30 2sinx x+ = ; 0 ; 360x . (3)
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(b) On the axes below, the graph of ( ) 2sinf x x= has been drawn; 0 ; 360x .
On the same axes sketch the graph of ( ) ( )cos 30g x x= + . (3)
PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 23 of 30
(c) Use the graphs to determine the values of 0 ; 360x for which:
(1) ( ) ( ). 0f x g x . (2)
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(2) 4sin 3 cos sinx x x − . (2)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 24 of 30 QUESTION 13
During the moderation process after the mini prelim that was out of 150 marks it was
decided to adjust the raw scores. Two options were discussed.
Option One: Add 7,5 marks to each student’s raw score.
Option Two: Add 10% of the marks they did not get.
For example:
Raw Scores Option 1 Option 2
100 107,5 105
80 87,5 87
(a) How will option one affect the raw median and standard deviation? (2)
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(b) How will option two affect the raw median and standard deviation? (3)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 25 of 30 QUESTION 14
In the diagram diameter AOB intersects chord CE at D so that CE ED= .
If and : 3 : 2OA r AB CD= = , show that ( )3 5
units.3
rEB
−= (8)
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PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 26 of 30 QUESTION 15
Refer to the figure below.
• D and E are points on BC and AC
respectively of ABC
• AD and BE intersect at F
• BD CE=
• AD BE=
• FDCE is a cyclic quadrilateral.
(a) Prove:
ABD BCE (4)
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(b) Write down an angle equal to 1A . (1)
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(c) Prove that ABC is an equilateral triangle. (3)
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SECTION B: 77
PRELIMINARY EXAMINATION: MATHEMATICS PAPER II Page 27 of 30 EXTRA LINES: (Please number carefully if you use this space!)
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