Greetings from Brasil...
Given the function:
F(X) = 3X
We know that F(X) = Y, so rewriting the function:
Y = 3X
Let's check what is the inverse function of F(X). Just change the X for the Y and vice versa
Y = 3X
X = 3Y isolating Y
Y = X/3
So the inverse of function F(X) is
F⁻¹(X) = G(X) = X/3
