mathematics: paper ii matric preliminary …
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MATHEMATICS: PAPER II
MATRIC
PRELIMINARY EXAMINATIONS SEPTEMBER 2021
Marks: 150 Examiner: A Abatzidis Time: 3 Hours Moderator: D Garofoli Reading Time: 10 Min
EXAMINATION NUMBER:
PLEASE READ THESE INSTRUCTIONS CAREFULLY:
1. This question paper consists of 28 pages and a separate Information Sheet.
Please check that your paper is complete.
2. Additional space is given on pages 29 and 30. If this space is used, indicate clearly
which question is being answered.
3. Read the questions carefully.
4. Answer ALL the questions on the question paper. Ensure that you have written your
examination number in the space provided above.
5. Diagrams are not necessarily drawn to scale.
6. All the necessary working details must be clearly shown.
7. Answers only will not necessarily be awarded full marks.
8. Approved non-programmable and non-graphical calculators may be used unless otherwise
stated. Ensure that your calculator is in DEGREE mode.
9. Give answers correct to ONE decimal digit, where necessary.
10. It is in your own interest to write legibly and to present your work neatly.
______________________________________________________________________________
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 2 of 30
SECTION A QUESTION 1 A (6; – 4), B (8 ; 2), C (3; a) and D (b ; c) are points on the Cartesian plane. (a) Determine the value of a if A, B and C are collinear. (3) (b) Determine the value of b and c if B is the midpoint of AD. (3) (c) Find the angle of inclination of AB. (2) [8]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 3 of 30
QUESTION 2 Tassy measured the heights of several plants (in cm) at different stages after planting, and she
recorded the following data:
x = days after
planting 14 20 8 15 18 11 13
h = height (cm) 6 11 3 8 10 4
Tassy lost the record of the last height, but she does know that the equation of the regression
line is:
h = 0,72x – 3,31
(a) Estimate, to the nearest centimetre, what the last recorded height was. (2)
(b) Calculate the correlation coefficient for the data relating to the first 6 plants correct to
FOUR decimal digits. (i.e. ignoring the last column). (2)
(c) Some time later, Tassy found another plant’s height 25 days after planting to be 20 cm.
Comment on how surprised (or not) Tassy would be in light of her previous results. (2)
[6]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 4 of 30
QUESTION 3 Refer to the figure: A circle has equation
2 22 6 15x x y y− + + = (a) Find the coordinates of the centre, A, and the radius of the circle. (4) (b) Determine the co-ordinates of B and C, the x-intercepts of the circle. (4)
A
D (5 ; – 6)
x
y
O B C
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 5 of 30
(c) Determine the equation of the tangent to the circle at D (5 ; – 6), given A (1 ; – 3). (4) (d) Determine the area of ΔABC. (3)
(e) Given that another circle ( ) ( )2 2
1 1x y b− + − = touches this circle with centre A at one
point only, give one possible value of b. (2)
[17]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 6 of 30
QUESTION 4 (a) Refer to the following statements below labelled A to C and match the statements to
their most expected histogram labelled D to F. (3)
A.
The age at death in
developed countries
(First world countries).
B.
The salaries of all
employees at a major
corporate company.
C.
The results of a test
where some of the
students had been taught
and others had not been
taught the section of work
covered.
D.
E.
F.
Fill in the answers in this block:
A →
B →
C →
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 7 of 30
(b) The diagram below shows a cumulative frequency curve for the lengths of telephone calls
from a home landline during the first 6 months of the year.
Time (minutes)
State whether each of the following statements are True or False: (4)
(1) The distribution of these times is skewed.
(2) The majority of the calls last longer than 6 minutes.
(3) The majority of the calls last between 5 and 10 minutes.
(4) The majority of the calls are shorter than the mean length.
5 10 15 20 25 30
20
40
60
80
100
120
140
160
x
f
Cum
ula
tive
freq
uen
cy
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 8 of 30
(c) A group of athletes frequently run round a cross-country course in training. The box and
whisker plots below represent the times, in minutes, taken by athletes A, B, C and D to
complete the course a certain number of times.
Time (minutes)
(1) Compare the times taken by athletes C and D. Include variability and
skewness in the analysis. (4)
26 27 28 29 30 31 32 33 34 35 360
x
f
A
B
C
D
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 9 of 30
(2) Which of the athletes A or B would you pair up to race and possibly win against
(i) C ? Justify your choice. (2)
(ii) D ? Justify your choice. (2)
(d) The following information summarises the year marks for a class of 20 students.
( )20 20
2
1 1
1560 1220i i
i i
x x x= =
− = =
Determine the standard deviation for the class. (2)
[17]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 10 of 30
QUESTION 5
(a) Given: sin20op =
Express each of the following in terms of p, showing all working:
(1) sin200o (1)
(2) sin50o (4)
(b) Given that θ ; 2θ , and 3θ are the angles of a triangle evaluate, without the use of a
calculator: 2 2 2cos cos 2 cos 3 + + (4)
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 11 of 30
(c) Evaluate, without the use of a calculator:
sin124 .sin64 sin214 .sin26o o o o+ (5)
[14]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 12 of 30
QUESTION 6
The JP Morgan Chase Tower in Houston is a prism with a height of 305 metres. The cross section is a square with an isosceles triangle removed. Refer to the dimensions as shown. Aerial view JP Morgan Chase Tower
50 m
25 m
305 m
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 13 of 30
Determine: (a) the volume of the tower. (3) (b) the surface area of the tower. (4)
[7]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 14 of 30
QUESTION 7 Refer to the figure: BD is a diameter and ABF is a tangent.
ˆ 2ABE x= and AB = EB. Determine the following angles in terms of x , giving reasons:
(a) 1C
(b) ˆECD
(c) 1E
(d) D
(e) 2E
[7]
76 marks
E
D
B
A
C
F
2x
1
2
2
2x
1
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 15 of 30
SECTION B QUESTION 8
(a) Prove:
( ) ( )( ) ( )
2 2cos 45 sin 452sin
cos30 cos 30 sin30 sin 30
o o
o o o o
A AA
A A
− − −=
+ + + (5)
(b) Determine the general solution: 33tan 2 tan2x x= (6)
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 16 of 30
(c) Given: 2 1 cos2tan
1 cos2
PP
P
−=
+
(1) Prove the identity. (5) (2) For which values of P will the identity be undefined? (3)
[19]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 17 of 30
QUESTION 9 (a) Marianne is riding with the cable car from Station A to Station B, the highest point at the
top of Mount Glacier. The ride takes 16 minutes with the cable car travelling at an average speed of 2 metres per second. Assuming the cable car moves in a straight line forming a 25o angle of elevation from Station A, find the height of Mount Glacier correct to the nearest metre. (4)
25o
B
Cable •
A
Mount Glacier
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 18 of 30
(b) Dave is constructing a portable basketball net for an indoor court. The structure is made from a metal tubing support, with dimensions as shown in the diagram (not drawn to scale).
B
C
92o
H
78o
72o
A
1,3 m
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 19 of 30
Determine the length of tubing that Dave needs for AB. (6)
[10]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 20 of 30
N
M
P
RQ
QUESTION 10 Refer to the figure: P is the centre of the circle with a radius of 73 units. M is the midpoint of chord QR. N is a point on PR such that PN = 40 units. MN⊥ PR.
(a) Give a reason why PM⊥ QR. (1) (b) Determine, giving reasons, the length of MR, correct to the nearest whole number. (4) [5]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 21 of 30
QUESTION 11
(a) Given: Δ XYZ and Δ LMN such that ˆ ˆ ˆ ˆ ˆ ˆ; andX L Y M Z N= = = .
Using the given diagram, prove the theorem which states that if two triangles are equiangular, then their sides are in proportion.
i.e. Prove that XY XZ
LM LN=
Construction: (1) Proof: (5)
Z
X L
Y M N
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 22 of 30
(b) In the diagram, O is the centre of the circle with diameter AOB. The tangent through C intersects AD produced at F.
OD⊥AC and CF⊥AF
Prove that:
(1) Δ FCD ||| Δ CAB (4)
1
E
D
F
B
O
C
A
1
1
1
2
2
2
2
3
3 1
2
4
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 23 of 30
(2) FC.CB = 2 FD.AE (4)
(3) 1 2ˆ ˆA A= (3)
[17]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 24 of 30
QUESTION 12 So far, all the Analytical Geometry that we have done has been two-dimensional, in the co-ordinate plane. Solids in space are generally three-dimensional. Co-ordinates in the plane can be extended to co-ordinates in space. For this we need three co-ordinate axes that are mutually perpendicular to each other and pass through the origin O. These are usually the x, y and z-axes as shown in the sketch. This gives three co-ordinate planes.
• The (horizontal) xy-plane where z = 0.
• The (vertical) yz-plane where x = 0.
• The (vertical) xz-plane where y = 0.
❖ A point P in this system will have three co-ordinates ( ); ;P x y z .
❖ The distance between two points ( ); ;A A AA x y z and ( ); ;B B BB x y z becomes
( ) ( ) ( )2 2 2
A B A B A BAB x x y y z z= − + − + −
❖ And the midpoint M between A and B becomes
; ;2 2 2
A B A B A Bx x y y z zM
+ + +
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 25 of 30
(a) Determine the equation of the sphere with centre ( ); ;C h k l and radius r.
Note: A sphere is the set of all points ( ); ;P x y z such that the distance PC = r. (2)
(b) Determine the centre and the radius of the following sphere:
2 2 2 4 2 6 2 0x y z x y z+ + + + − − = (3)
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 26 of 30
45 90 135 180 225 270 315 360
−0.5
−0.25
0.25
0.5
0.75
1
1.25
1.5
x
y
[5] QUESTION 13 Deborah is approximating the phases of the moon by using trigonometric functions as models.
The function f has equation ( ) sinf x a x b= + and this can be used to estimate the dates for the
moon phases for August 2021 in the southern hemisphere.
August 2021
90o 180o 270o 360o
(a) Give the value of a and b. (2)
f g
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 27 of 30
(b) The model assumes a 28-day moon cycle, and on 1 August 2021 Deborah saw the last quarter (half moon, waning). On what date in August did Deborah see the new moon? (2)
(c) State the equation of g in the form ( ) ( )cosg x m x p q= − + . (3)
(d) The graph of g shows the moon phases for September 2021.
On what date in September can Deborah expect to see the new moon? (2)
[9]
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 28 of 30
S
P
T
RQ
QUESTION 14 Refer to the figure: In ΔPTR: PT ǀǀ QS, RS = 5 units, ST = x units,
RQ = 3x + 1 units, PQ = 6 units
(a) Calculate the value of x, with reasons. (4)
(b) Assuming x = 3 and area ΔQRS = p units2, find the area of QSTP in terms of p. (5)
[9]
74 marks
TOTAL: 150 marks
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MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 29 of 30
ADDITIONAL SPACE
REMEMBER TO CLEARLY INDICATE AT THE QUESTION THAT YOU USED THE ADDITIONAL SPACE TO ENSURE THAT ALL ANSWERS ARE MARKED.
MATRIC MATHEMATICS PAPER II: SEPTEMBER 2021 Page 30 of 30
ADDITIONAL SPACE