Which represents the inverse of the function f (x) = 4x?

To find the inverse function, interchange the variables and solve for y.

f⁻¹ (x) = x/4

An inverse of the function is when you switch the variables around, or solve for f (x). I'm going to make f (x) y, because it is just the same thing. So y=4x. Divide by 4, so x=y/4. Then you can switch the variables so y is on the outside, or the dependent variable, and the answer is y=x/4, or y=1/4x.