Hi to all again =) I have 2 questions about directioanl derivate & Triple integral things.

1) The temparature in a rectangular box is approximated by T(x,y,z)=xyz(1-x)(2-y)(3-z) \;\; ,\;\; 0\;{\leq}\;x\;{\leq}\;1 \; , \; 0\;{\leq}\; y\;{\leq}\;2 \;,\; 0\;{\leq}\;z\;{\leq}\;3<br />
If a mosquito is located at  (1/2\;,1\;,1), in which direction should it fly to cool off as rapidly as possible?

2 A wedge is cut from a right circular cylinder of radius R by a plane perpendicular to the x-axis of the cylinder and a second plane that meets the first on the axis at an angle of \theta degrees. Set up an evaluate a triple integral for the volume of the wedge.

These two are questions and i don't know where to begin so i couldn't make any progress.

Gonna be very appriciated for any help.