Question

the x values of stationary points of y=x^3-3x^2 are:

Answer 1

x^3-3x^2=0
x^3-3x^2=-4

Answer 2

This is similar to the other question you asked ( http://openstudy.com/updates/4f6e5127e4b0772daa0898c6), i.e.:
The stationary points are where the derivative of f(x) equals zero.
So you need to differentiate f(x) and equate the resulting expression to zero. Then solve to find x.