Question

If f(x) = 1/9x - 2, what is f^-1 (x)

Answer 1

Greetings from Brasil...

For reverse function, just invert the X by the Y and vice versa.

Note that F(X) = Y and F⁻¹(X) = Y⁻¹

F(X) = 1(9X - 2) ⇔ Y = 1(9X - 2)

replacing X with Y⁻¹

X = 1(9Y⁻¹ - 2)

Y⁻¹ = (2X + 1)/9X