The inverse of this function is y = x -

You can find the inverse of any function by switching the x and y values and then solving for the new y value. Once you've done that, what will be left over is the inverse function.
y =
----> Swap x and y
x =
-----> Subtract 3/4 from both sides.
x -
= y ----> rearrange to appropriate order
y = x -

And that is your inverse function.