We're going to need to figure out the derivative of the top. So if I have 3 Q sine Q and I'm wanting the derivative of this in terms of Q, we realize we have two Q's here, there's one here and there's one with the sine Q. So the derivative of just plain old Q would be one times everything else. Plus the derivative of sine Q is cosine Q and that gets times everything else. So the derivative of that numerator is going to be 3 sine Q + 3 Q cosine Q. So the quotient rule says the derivative of the top times the bottom minus the derivative of the bottom, which is three Q ^2 times the top all over the bottom squared. Now it's a matter of foiling things out and distributing and then combining like terms. So we get -6 Q cubed sine Q - 9 sine Q + 3 Q to the 4th cosine Q - 9 Q cosine Q all over the quantity Q ^3 - 3 ^2.