Diketahui f(x )= x + 2 g(x) = 4 – 3x dan h(x)= 2x + 3 jika (f o g o h)-¹ a = 1 nilai dari a =
goh (x) = g (h(x))
= 4 – 3 h(x)
= 4 – 3 (2x + 3)
= 4 – 6x – 9
= -6x – 5
fogoh (x) = f (goh(x))
= goh(x) + 2
= -6x – 5 + 2
= -6x – 3
Bila mencari invers, misalkan fungsi yg akan diinvers dulu, lalu cari nilai x
misalkan fogoh (x) = p
fogoh (x) = -6x – 3
p = – 6x – 3
6x = – p – 3
x = (- p – 3)/6
(fogoh)^-1 (x) = (-x-3)/6
(fogoh)^-1 (a) = 1
(-a – 3)/6 = 1
-a – 3 = 1 × 6
-a – 3 = 6
– a = 6 + 3
-a = 9
a = -9