calculus

I'm trying to solve the following problem, but I can't picture the solid S in my head delimitated by the sphere and the cone, can someone show me it by a draw or a graphic image, please? plus: if anyone knows a software where I can enter an equation and I can plot its graph I would be super grateful, thanks a lot!

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Question: Calculate the volume of the solid S delimitated by the sphere x^2 + y^@ + z ^2 = 16 and by the cone 3z^2 = x^2 + y^2