`(cosx)/cos(x-2y)=lambda=>tan(x-y)tany=`

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

(sinx-siny)/(cosx+cosy)=tan(x-y)/(2)

Prove that: (sin x-sin y)/(cos x+cos y)quad =tan(x-y)/(2)

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

If (cos(x-y))/(cos(x+y))=(m)/(n), then write the value of tan x tany

(dy)/(dx)coty=cos(x+y)+cos(x-y) A) log(secy+tany)=2cos x+c B) log(cosecy-coty)=2sinx+c C) log(cosy-coty)=2cosx+c D) cosy-coty=c.e^(cosx)

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

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

prove that tan ((pi) / (4) + (1) / (2) cos ^ (- 1) ((a) / (b))) + tan ((pi) / (4) - (1) / (2) cos ^ (- 1) ((a) / (b))) = (b) / (a) cos ^ (- 1) ((cos x + cos y) / (1 + cos x cos y) ) = 2tan ^ (- 1) ((tan x) / (2) (tan y) / (2))