lf `cos x + cosy-cos z = 0 = sin x + sin y + sin z` then `cos((x-y)/2)=`

If cos x + cos y + cos z = 0 = sin x + sin y + sin then tan (xy) =

If cos x + cos y + cos z =0 = sin + sin y +sin z then tan (x-y) =

cos x + cos y + cos z = 0 and sin x + sin y + sin z, then cos ^(2) (( x-y)/( 2)) =

cos x + cos y + cos z = 0 and sin x + sin y + sin, then cos ^ (2) ((xy) / (2)) =

If cosx + cosy + cosz = 0 and sinx + siny + sinz =0 , then show that cos (x-y) + cos(y - z) + cos(z - x) = - 3/2.

If cos x+cos y+cos alpha=0 and sin x+sin y+sin alpha=0, then cot ((x+y)/(2))

If cos x + cos y + cos alpha = 0 and sin x + sin y + sin alpha = 0 then cot ((x + y) / (2)) =

If cosx + cosy + cosz = 0 "and" sinx + siny + sinz =0, "then show that" cos (x-y) + cos(y - z) + cos(z - x) = - 3/2.

If cos x + cos y + cos alpha = 0 and sin x + sin y + sin alpha = 0 , then cot((x+y)/(2)) =