bila f(x)= x^3 dan g(x)=3x-4 maka (g-^1○f-^1)(8)

jawab
g⁻¹ o f⁻¹ (x) = (fog)⁻¹(x)

f(x) = x³
g(x)= 3x - 4

misal 
y = (g⁻¹ o f⁻¹)(8)
y =  (fog)⁻¹(8) → fog(y)= 8
f{g(y)} = 8
f(3y- 4) = 8
(3y - 4)³ = 8
(3y- 4)³ = (2)³

3y - 4 = 2
3y = 6
y = 2
maka  (g⁻¹ o f⁻¹)(8)= 2