How do I find a stationary point on the curve?

Well that depends on the curve, but if it is a quadratic, we can do it with the following method. We know that differentiating the equation of the curve will give us the equation of the tangent to that curve at this point. Therefore, since the gradient of the tangent to a stationary point will be zero, we can set the differentiated equation to zero and solve for x. Once we solved for x, we can plug that value back into the original function to get the y value.