(cos x)/(cos(x-2y))=lambda rArr tan(x-y)tan y=

(cos x) / (cos (x-2y)) = lambda rArr tan (xy) tan y =

(cos x )/( cos (x-2y))= lambda implies tan(x-y) tan y=

If cos x=lambda cos(x-2y) then value of (1-lambda)/(1+lambda)= A) tan(x-y)cot y B) cot(x-y)tan y C) tan(x-y)tan y D) 0

cos ^(-1) ""((cos x + cos y)/(1+cos x cos y))= 2 tan ^(-1) (tan ""(x)/(2) tan ""(y)/(2))

cos x + cos y = (4) / (5), cos x-cos y = (2) / (7) rArr14tan ((xy) / (2)) + 5cot ((x + y) / (2)) =

cos x + cos y = (4) / (5), cos x-cos y = (2) / (7) rArr14tan ((xy) / (2)) + cot ((x + y) / (2)) =

Show that cos^(-1) ((cosx+cos y)/(1+cos x.cosy))= 2tan^(-1)(tan(x/2).tan(y/2)) .

If (cos x)/(cos y)=2 and cos(x-y)=(sqrt(3))/(2) then tan y=