Page 21 - Grab Me SPM Add Mathematics Form 4,5

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Example 8 (b) (i) m cos px – 1 = –4
Draw a graph of y = –4 on the graph.
The diagram below shows the graph of There is only 1 point of intersection,
y = m cos px – 1 for 0  x  p. therefore the number of solution is 1.
y (ii) m cos px = –2
y = m cos px – 1 m cos px – 1 = –2 – 1
2 m cos px – 1 = –3
1 Draw a graph of y = –3 on the graph.
x
0 1 1 3 � There are 2 points of intersection, therefore
–1 –� –� –�
–2 4 2 4 the number of solutions is 2.
–3
–4 Example 9
(a) State the values of m and p. The diagram below shows the graph of
(b) Find the number of solutions for each of the y = m sin nx for 0  x  2p.
following. y
(i) y = –4 (ii) m cos px = –2
Solution 3 y = m sin nx
(a) When x = 0 and y = 2, m cos 0 – 1 = 2
m = 3 0 � 2� x
When x = p and y = 2, 3 cos pp – 1 = 2
cos pp = 1 –3
pp = 2p
p = 2 State the values of m dan n.

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Ch 6_Grab Me SPM AddMaths F5.indd 195 13/05/2022 9:22 AM