jika F(x)=3x-1 : 2x+4 tentukan nilai F-1(5)

jawab

fungsi invers

f(x) = (3x -1) / (2x + 4)

f⁻¹ { (3x-1) /(2x + 4)} = x

f⁻¹ (5) = ...

(3x  - 1) / (2x + 4) = 5
5(2x  + 4) = 3x - 1
10x + 20 = 3x - 1
7x = - 21
x = - 3

f⁻¹ (5) = - 3