Triple Integrals Problem

[marcusnicolas1]

I downloaded the Graph3D 2.42 version. It seems as though I can not longer plot the function of square root of -X^2 -Y^2, It gives me a box with nothing inside of it. Also, I have been trying to plot a sphere and can not do so. I know a sphere is X^2 + Y^2 +Z^2 equals a number. However I can not seem to plot that. Can anyone help me with this please? THank you.