# Homework Help: Partial derivatives review

1. Aug 31, 2006

Ok i got this problem...
T(x,y,z,t)= -2xy^2+e^(-3z)cos(5x-.75t)
taking the partial derivative with respect to x first, so i break the problem apart with the left and right sign of the addition side

so i get...
-2y^2 for the left side and then am stubling on the right side, im think just chain rule since e^(-3z) is constant right? so I get -sin(5x-.75t)5 from the right side.

any help

2. Aug 31, 2006

### quasar987

So the final answer for $\partial T/\partial x$ is what according to you?

3. Aug 31, 2006

its -2y^2-e^(-3z)*sin(5x-.75t)5 I THINK, butttt... i have a voyage 200 near me and when i check it, its giving me a error and I don't trust myself enough to think its right...

Last edited: Aug 31, 2006
4. Aug 31, 2006

### quasar987

That's the correct answer. What's a voyage 200?

5. Aug 31, 2006