Question 1021851
The critical points on the graph of the function are those where you can find local extrema (derivative either 0 or does not exist). Since the function is a polynomial, the derivative exists everywhere, and you only have to set the derivative equal to 0 to find the critical points.

For f(x) = {{{x^4 - 2x^2}}}, y' = {{{4x^3 - 4x}}}.

Setting y' to 0, we get x = -1,0,1.

You can now finish the solution.