00:01
So in this question, they say, draw a branch diagram and then write a chain rule formula for each derivative.
00:06
Here i have the partial of w with respect to x and the partial w with respect to y.
00:12
If w is a function of r s and t, and each of r s and t are functions of x and y.
00:21
So let's see here, we've got w, which is some function of r s and t initially, and then each of r, s and t, they are functions of x and y.
00:36
So r is a function of x and y, s is a function of x and y, and t is a function of x and y.
00:44
So now, if i want my partial derivative of w with respect to x, i'm going to look at each branch that leads from w to x.
00:59
We multiply down each of the branches.
01:03
So on the left, i start with the partial w with respect to r times the partial derivative of r with respect to x...