If `tan^(-1)x+tan^(-1)y+tan^(-1)z=pi/2,t h e n` (a) `x+y+z-x y z=0` (b) `x+y+z+x y z=0` (c) `x y+y z+z x+1=0` (d)`x y+y z+z x-1=0`

If tan^(-1)x+tan^(-1)y+tan^(-1)z=pi, show that x + y + z = xyz.

If cos^(-1)x+cos^(-1)y+cos^(-1)z=pi,t h e n (a) x^2+y^2+z^2+x y z=0 (b) x^2+y^2+z^2+2x y z=0 (c) x^2+y^2+z^2+x y z=1 (d) x^2+y^2+z^2+2x y z=1

Prove that tan^(-1)x+tan^(-1)y+tan^(-1)z=tan^(-1)((x+y+z-xyz)/(1-xy-yz-zx))

If cot^(-1)x+cot^(-1)y+cot^(-1)z=pi/2,x , y , z >0a n dx y<1, then x+y+z is also equal to (a) 1/x+1/y+1/z (b) x y z (c) xy+yz+zx (d) none of these

Solve x + y = 7 , y + z = 4 , z + x = 1

IF sin^(-1) X+ sin^(-1) y+ sin^(-1) z= pi , then prove that x^4 +y^4+ z^4 +4x^2 y^2 z^2 = 2(x^2 y^2 +y^2 z^2+z^2x^2).

The determinant |x p+y x y y p+z y z0x p+y y p+z|=0 if x ,y ,z

Solve the system: x + y - 2z = 0, 2x - 3y + z = 0, 3x - 7y + 10z = 0, 6x - 9y + 10z = 0.

If cos^(-1) x + cos^(-1) y + cos ^(-1) z = pi and 0 lt x,y,z lt 1 show that x^(2) +y^(2) +z^(2) +2xyz = 1

If x, y, z are in A.P. and tan^(-1) x, tan^(-1) y and tan^(-1)z are alos in A.P. then