# Functions of several variables

1. Oct 26, 2008

### muso07

If I have $$V(t,x,y,z)=(x/(x^{2}+y^{2}+z^{2}))sin(t+\pi/4)$$, does $$dV/dt=(x/(x^{2}+y^{2}+z^{2}))cos(t+\pi/4)$$? I'm not too crash hot with functions of several variables...

2. Oct 26, 2008

### Pere Callahan

That is correct. (Unless x,y,z, depend on t as well)