00:01
In this exercise, we want to find the partial derivative, the partial for z with respect to x, for z equals sine of three x, cosine of three y.
00:10
So in this case, when we take a partial derivative with respect to some variable, here we have partial z, respect to x, we know that we have to treat the other variable as if it is a constant.
00:23
So in this case, we have another variable y, and because we're taking respect to x, we treat y as a constant.
00:30
So let's take the partial derivatives of both sides.
00:33
So we have the partial equals.
00:37
So cosine of 3y, if we treat it as a constant, we can kind of just bring it to the side here.
00:42
And then take the partial of just sine of 3x...