When we find our derivative here at the DYDX, remember that the four is a coefficient. So we have four times cosine X times cotangent X. So when we do the derivative of this actually that was Y equal. When we do the derivative of this, we're going to have to use the product rows. So DYDX. If we think about the derivative of cosine, that's negative sign. So the derivative of the cosine times everything else. Plus now we need the derivative of the cotangent times everything else, and the derivative of the cotangent is negative cosecant squared X. So when we simplify this up, we get -4 sine X cotangent X -, 4 cosine X cosecant squared X. Now we would have -4 sine X cotangent as cosine over sine. So the sines are going to cancel -4 cosine X cosecant squared X here at the end. So we get -4 cosine X -, 4, cosine X, cosecant squared X.