You can find the stationary points by differentiating the equation and then solving it for zero. What this means, is that you can take the power of the Xs in the equation, and differentiate by bringing the power to the front, and then subtracting one from the power in front of the X. For example, for y = X^2, differentiating it would give 2x. You can then set f(x) = 0, and find the value of x for which f(x) is equal to 0 by solving like an algebraic equation. This will give you the stationary x coordinate. You can then use this value and substitute it in for x in the original equation to solve for f(x) or y. The gives you the y coordinate of the stationary point.