Differentiate f(x) with respect to x.You get f'(x) = 2x - 2Turning points occur when the derivative of f(x) = 0. In other words, when f'(x) = 0. This occurs when x=1.Now to determine if maximum or minimum, find f''(x) by differentiating f'(x) wrt x. f''(x) = 2. Since 2 is greater than 0, we know from theory that this point must be a minimum.