If `x+y+z=0` , then `x^2+x y+y^2` equals `y^2+y z+z^2` (b) `y^2-y z+z^2` (c) `z^2-z x+x^2` (d) `z^2+z x+x^2`

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

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

What should be added to x y+y z+z x to get x y-y z-z x ? (a) -2x y-2y z-2z x (b) -3x y-y z-z x (c) -3x y-3y z-3z x (d) 2x y+2y z+2z x

What should be added to x y+y z+z x to get x y-y z-z x ? -2x y-2y z-2z x (b) -3x y-y z-z x -3x y-3y z-3z x (d) 2x y+2y z+2z x

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

If |y z-x^2z x-y^2x y-z^2x z-y^2x y-z^2y z-x^2x y-z^2y z-x^2z x-y^2|=|r^2u^2u^2u^2r^2u^2u^2u^2r^2| , then r^2=x+y+z b. r^2=x^2+y^2+z^2 cdotu^2=y z+z x+x y d. u^2=x y z

If x + y = 2z then (x)/(x-z) +(z)/(y-z) = ?

Multiply: x^2+y^2+z^2-x y+x z+y z\ by x+y-z