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

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

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+cosalpha=0 and sinx+siny+sinalpha=0 then cot((x+y)/2)= ................. A) sin alpha B) cos alpha C) cot alpha D) sin ((x+y)/(2))

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

If sin x + sin y> = cos alpha cos x, AA x in R then sin y + cos alpha =

lf_ (cos x + cos y-cos z = 0 = sin x + sin y + sin) then cos ((xy) / (2)) =

If cos(x - y)= -1 , show that cos x + cos y = 0 and sin x + sin y = 0 .

If x sin ^ (3) alpha + y cos ^ (3) alpha = sin alpha cos alpha and x sin alpha-y cos alpha = 0 then x ^ (2) + y ^ (2) =