[tan^(-1)((xy)/(zr))+tan^(-1)((yz)/(xr))+tan^(-1)((xz)/(yr))=],[(a)pi],[(c)0]

If x^(2)+y^(2)+z^(2)=r^(2), thentan ^(-1)((xy)/(zr))+tan^(-1)((yz)/(xr))+tan^(-1)((xz)/(yr)) is equal to pi(b)(pi)/(2)(c)0(d) none of these

If x^(2)+y^(2)+z^(2)=r^(2) and x,y,z>0, then tan^(-1)((xy)/(zr))+tan^(-1)((yz)/(xz))+tan^(-1)((zx)/(yr)) is equal to

If x^(2)+y^(2)+z^(2)=r^(2) , then Tan^(-1)((xy)/(zr))+Tan^(-1)((yz)/(xr))+Tan^(-1)((xz)/(yr))=

Prove the followings : If tan^(-1)((yz)/(xr))+tan^(-1)((zx)/(yr))+tan^(-1)((xy)/(zr))=pi/2 then x^(2)+y^(2)+z^(2)=r^(2) .

If x^2 + y^2 + z^2 = r^2 and x, y, z > 0 , then tan^-1((xy)/(zr))+tan^-1((yz)/(xr))+tan^-1((zx)/(yr)) is equal to

If r^2 = x^2 + y^2 + z^2 , then prove that tan^(-1)((yz)/(rx))+tan^(-1)((zx)/(ry))+tan^(-1)((xy)/(rz))=pi/2