[" Q.7.If "cos^(-1)x+cos^(-1)y+cos^(-1)z=pi" then prove that : "],[qquad x^(2)+y^(2)+z^(2)+2xyz=1]

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

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

If (i) cos^(-1) x + cos^(-1) y + cos^(-1) z = pi , prove that : x^(2) +y^(2) +z^(2) + 2xyz = 1 (ii) If sin^(-1) x + sin^(-1) y + sin^(-1) z = pi/2 , prove that : x^(2) +y^(2) +z^(2) +2xyz = 1

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

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