Question

Jika f(x)= 3x-4 dan g(x)=3-4x.Tentukanlah (g o f) -1 dan (x) dan (f o g) -1 (x)

Answer 1

F(x) = 3x - 4
f⁻¹(x) = (x + 4)/3
g(x) = 3 - 4x
g⁻¹(x) = (3 - x)/4

(g o f)⁻¹ (x) = f⁻¹ o g⁻¹
= f⁻¹(3 - x)/4
= ((3 - x)/4 + 4)/3
= (3 - x + 16)/12
= (19 - x)/12

(f o g)⁻¹(x) = g⁻¹ o f⁻¹
= g⁻¹(x + 4)/3
= (3 - (x + 4)/3)/3
= (9 - x - 4)/9
= (5 - x)/9