Derivative Of SineDrag "A" and look at the trace for f ' (x). What function does it look like? Now think about the features of a derivative graph. When f(x) has max's and min's, the derivative should have roots. When f(x) gets steepest, the derivative should have max's and min's. Think about where the sine graph has these features, and how that matches up with the cosine graph.... Dave Matthews, Created with GeoGebra |