Integrated Programme/mainstream
Secondary Three Mathematics
Name: ___________________________ (
)
Class: _________ Date: _____________
Term 3 : Unit 1
Assignment 3
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Trigonomertic Functions
Question 1:
The function f(x) = 3 cos kx – 2 is defined for 0o  x  360o , where k is a constant.
(a) Given that f intersects the x-axis at 4 points, state the
(i) value of k,
(ii) amplitude and period of f.
(b) Sketch the graph of f.
Question 2:
x
Given that y  7  4 sin , find
2
(a) the amplitude and period of y, (Give your answer in degree.)
(b) the coordinates of the maximum and minimum points of the curve in the interval
0o  x  480o
x
(c) Hence, sketch the graph of y  7  4 sin .
2
Question 3:
On the same diagram, sketch the graphs of y = tan x and y = 3 cos x + 1 for the interval
0o  x  360o .
tan x  1
 cos x .
Hence, state the number of solutions in this interval for the equation
3
Question 4:
Sketch on the same diagram, the graphs of y = 3 sin x and y = 2 cos 2x for the interval
0o  x  360o . Hence, state the number of solutions in this interval of the following
equations.
(a) cos 2x = 0.8
(b) cos 2x = 1.5 sin x
(c) 2 cos 2x – 3 sin x = 1