Which equation can be simplified to find the inverse of y=2x^2

The question is asking us to find the inverse of the function: f(x) = 2 x^2. The original function is: y = 2 x^2. First we have to interchange x and y and then to solve the function for y. So the 1st step: x = 2 y^2. Then: y^2 = x / 2 . Finally we have to take the square root of both sides of equation: y = sqrt( x / 2 ). The inverse is: f^(-1) ( x ) = sqrt( x / 2 )