If `cosx= tany, cosy= tanz and cosz= tanx`, prove that `sinx= siny= sinz = sin18^@`

If cosx=tany,cosy=tanz and cosz=tanx , then sin^2x=?

If cosx=tany,cosy=tanz and cosz=tanx , then sin^2x=?

If cosx=tany ,cosy=tanz ,cosz=tanx , then the value of sinx is (a) 2cos18^0 (b) cos18^0 (c) sin18^0 (d) 2sin18^0

If cosx=tany ,cosy=tanz ,cosz=tanx , then the value of sinx is (a) 2cos18^0 (b) cos18^0 (c) sin18^0 (d) 2sin18^0

If cosx=tany ,coty=tanz ,cotz=tanx , then the value of sinx is (a) 2cos18^0 (b) cos18^0 (c) sin18^0 (d) 2sin18^0

Prove Geometrically cos(x+y)=cosx,cosy-sinx.siny and hence prove that cos(x-y)= cosxcosy+sinxsiny using unit circle concept ?

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

If sinx+siny = a, cosx+cosy = b, prove that sin(x+y) = (2ab)/(a^(2)+b^(2))