So instead of just writing h to the third power, which I could write over here, let me write h of t to the third power, just to make it clear that this is a function of t. h of t to the third power. Now, what is the derivative with respect to t of h of t to the third power? Now, you might be getting a tingling feeling that the chain rule might be applicable here. So let's think about the chain rule. The chain rule tells us, let me rewrite everything else, dv with respect to t is going to be equal to pi over 12 times the derivative of this with respect to t. If we want to take the derivative of this with respect to t, we have something to the third power. So we want to take the derivative of something to the third power with respect to something. So that's going to be, let me write this in a different color, maybe an orange.