If x=rcosthetacosphi,y=rcosthetasinphi,z=rsinthetax = r\\cos\\theta \\cos\\phi, y = r\\cos\\theta \\sin\\phi, z = r\\sin\\thetax=rcosthetacosphi,y=rcosthetasinphi,z=rsintheta, then x2+y2+z2x^2 + y^2 + z^2x2+y2+z2 is:
r2r^2r2
rrr
111
r2cos2thetar^2 \\cos^2 \\thetar2cos2theta