Question

G(x) = 4x – 1 dan (f○g)(x) = 8x – 1 maka f^-1 (-5)(x) = ...

Answer 1

(fog)(x) = 8x-1
f(g(x)) = 8x-1
f(4x-1) = 8x-1
f((4x-1+1)/4) = 8.((x+1)/4)-1
f(x) = 2.(x+1)-1
f(x) = 2x+2-1
f(x) = 2x+1

y = 2x+1
y-1 = 2x
x = (y-1)/2
f^-1(x) = (x-1)/2
f^-1(-5) = (-5-1)/2
f^-1(-5) = -6/2
f^-1(-5) = -3