Prove that : `tan^(-1)(y z)/(x r)+tan^(-1)(z x)/(y r)+tan^(-1)(x y)/(z r)=pi/2` , where `x ,\ y ,\ z >0` such that `x^2+y^2+z^2=r^2`

Prove that : tan (x-y)+tan (y -z) + tan (z-x)= tan (x-y)tan (y -z) tan (z-x) .

If tan ^(-1) x+tan ^(-1) y+tan ^(-1) z=(pi)/(2), then 1-x y-y z-z x=

If tan ^(-1) x+tan ^(-1) y+tan ^(-1) z=(pi)/(2) then x y+y z+z x=

Prove that tan(x - y) + tan(y - z) + tan(z - x) = tan(x - y) *tan(y -z)* tan(z -x) .

If tan^(-1) x + tan^(-1) y - tan^(-1) z = 0 , then prove that : x+ y + xyz = z .

If tan^(-1) x + tan^(-1)y + tan^(-1)z= pi then x + y + z is equal to

If tan^(-1) x + tan^(-1)y + tan^(-1)z= pi then x + y + z is equal to

If x^2+y^2+z^2=r^2,t h e ntan^(-1)((z y)/(x r))+tan^(-1)((x z)/(y r))+tan^(-1)((x y)/(z r)) is equal to pi (b) pi/2 (c) 0 (d) none of these