cos^(2)x+cos^(2)y-cos^(2)zquad " miniment value? "

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

Maximum value of cos^(2)x+cos^(2)y-cos^(2)z is

If x+y=z then cos^(2)x+cos^(2)y+cos^(2)z-2cos x cos y cos z is equal to

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 x , y ,z in [-1,1] such that cos^(-1)x+cos^1y+cos^(-1)z=3pi, then find the values of (1). x y+y z+z y and (2). x(y+z)+y(z+x)+z(x+y)

If x , y ,z in [-1,1] such that cos^(-1)x+cos^1y+cos^(-1)z=3pi, then find the values of (1) x y+y z+z y and (2) x(y+z)+y(z+x)+z(x+y)

If x , y ,z in [-1,1] such that cos^(-1)x+cos^1y+cos^(-1)z=3pi, then find the values of (1) x y+y z+z x and (2) x(y+z)+y(z+x)+z(x+y)

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