If sin^{-1}x+sin^{-1}y+sin^{-1}z=pi,prove that

(i) x(1-x^{2})^{1/2} +y(1-y^{2})^{1/2} +z(1-z^{2})^{1/2}=2xyz

(ii) x^{4} +y^{4} +z^{4} +4x^{2} y^{2}z^{2} =2(x^{2} y^{2} +y^{2} z^{2}+z^{2}– x^{2}

If sin^{-1}x+sin^{-1}y+sin^{-1}z=pi,prove that

(i) x(1-x^{2})^{1/2} +y(1-y^{2})^{1/2} +z(1-z^{2})^{1/2}=2xyz

(ii) x^{4} +y^{4} +z^{4} +4x^{2} y^{2}z^{2} =2(x^{2} y^{2} +y^{2} z^{2}+z^{2}– x^{2}