Find the inverse of the function f(x)=3/4x then graph the function and it’s inverse

To find the inverse of
.. y = 3/4x
you swap the variables and solve for y
.. x = 3/4y
.. y = 4/3x
Now you know
.. f⁻¹(x) = x

The graph of these can be seen at https://www.desmos.com/calculator/lipabvgmhz

The dashed orange line on the graph is y=x. It is there to help you see that the inverse function is the original function reflected across the line y=x.