If `cos^-1x+cos^-1y+cos^-1 z=pi, then ` (A) `x^2+y^2=z^2` (B) `x^2+y^2+z^2=0` (C) `x^2+y^2+z^2=1` (D) none of these

If cos^(-1)x + cos^(-1)y + cos^(-1)z = pi , then x^(2) + y^(2) + z^(2) + 2xyz is :

If cos^(-1)x+cos^(-1)y+cos^(-1)=pi, prove that x^(2)+y^(2)+z^(2)+2xyz=1

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

If sin^(-1)x +cos^(-1)y +sin^(-1)z=2pi then 2x-z+y is :

If cos^(-1)x+cos^(-1)y+cos^(-1)z+cos^(-1)t=4pi , then x^(2)+y^(2)+z^(2)+t^(2)=

If : cos^(-1)x+cos^(-1)y+cos^(-1)z=3pi, " then :" x (y+z)+y(z+x)+z(x+y)=

If cos^-1 x+cos^-1 y+cos^-1 z=pi and x+y+z= 3/2, then prove that x=y=z

If cos^(-1)x+cos^(-1)y+cos^(-1)z=pi, then x^(2)+y^(2)+z^(2)+xyz=0x^(2)+y^(2)+z^(2)+2xyz=0x^(2)+y^(2)+z^(2)+xyz=1x^(2)+y^(2)+z^(2)+2xyz=1

If cos^(-1) x + cos^(-1) y + cos^(-1) z = pi" , prove that " x^(2) + y^(2)+ z^(2) + 2xyz = 1 .

If sin^-1 x+sin^-1 y+sin^-1 z= pi prove that: x^4+y^4+z^4+4x^2y^2z^2=2(x^2y^2+y^2z^2+z^2x^20