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.