Triple Integrals Problem

[Snorre]

(12-24-2014 03:59 AM)marcusnicolas1 Wrote:  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.

Hello,

You're on the right path. As you've noticed a sphere can be definied by x²+y²+z²=r², so z=±√(r²-x²-y²).
In your first attempt you omitted the radius, which means you were plotting a sphere with radius r=0.
Just try again by first setting R:=10, then plotting √(R²-X²-Y²), and also -√(R²-X²-Y²).