00:02
Okay, so we need to find the second partial derivative of f with respect to x, y and z.
00:08
So we have fx equal to y times x squared plus y squared minus 2 times x squared times y over x squared plus y squared whole squared and fxy is equal to 2 times xy times x squared plus y squared minus 4 times x cubed times y over x squared plus y squared whole cubed and since f does not depend on z, the partial derivative with respect to z will be 0.
00:44
So f of x, y, z is equal to 0.
00:47
Now we need to find the second partial derivative of f with respect to y, z and x.
00:51
So we have fy equal to x times x squared plus y squared minus 2 times x times y squared over x squared plus y squared whole squared and since f does not depend on z, the partial derivative with respect to z will be 0.
01:09
So fy, z will be equal to 0.
01:14
Now for fy, z, x, since fy, z is equal to 0, the partial derivative with respect to x will also be 0.
01:23
So we get fy, z, x equal to 0.
01:26
Finally, we need to find the second partial derivative of f with respect to z, x and y...