I have attached an image of a problem I'm working through. 
I do get that the cube root of X^3 and cube root of y leaves as with the second line of the solution for the CDF.
But
A. I'm not sure where the 1/2 comes from?
B. I think it would make sense that the 1/2 be the height to integrate to 1..but it doesn't add up to 1??