What is the inverse of:
y = (2-x)^2
step 1: interchange the x and y variables, so your new equation is
x = (2-y)^2
step 2: solve this new equation for y
±√x = 2-y
y = 2 ± √x
y = (2-x)^2
x = (2-y)^2
step 2: solve this new equation for y
±√x = 2-y
y = 2 ± √x