Page 17 - Pra U STPM 2022 Penggal 1 - Mathematics (T)

Mathematics Term 1 STPM Chapter 1 Functions

The graph of y = kx (n even) is as follows:
n
k 0 k 0
1
y y
maximum point
x
O

x
O
minimum point
Figure 1.11(a) Figure 1.11(b)

Notice that the graph is symmetrical about the y-axis.

(b) If n is odd, the curve has a point of inflexion at the origin (0, 0). The graph of y = kx (n odd) is as follows:
n

k 0 k 0
y y

point of point of
inflexion inflexion
x x
O O

Figure 1.12(a) Figure 1.12(b)

Example 8

Sketch each of the following curves.
(a) y = 5x 4 (b) y = 3(x – 2) 5

5
Solution: (a) The graph of y = 5x has a (b) The graph of y = 3x has a point of
4
minimum point at the inflexion at the origin. The shape of
5
origin and is symmetrical the curve y = 3(x – 2) is similar of
about the y-axis. to that y = 3x but has a point of
5
inflexion at (2, 0).
y y 5 5
y = 3x y = 3(x – 2)
y = 5x 4

x
0 (2, 0)

x
O

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01a STPM Math T T1.indd 14 3/28/18 4:20 PM