Question

What is the inverse of the function f(x)=4x

Answer 1

f(x) = 4x
y = 4x
x = 4y (divide both sides by 4)
x/4 = y 
The inverse of f(x) is x/4

Answer 2

Here's my original function:

$y = 4x$

Now, I'll try to solve for "x=".

$x = \frac{y}{4}$

Once I have "x=", I'll switch x and y; the "y=" is the inverse.