Show that: `sin(x−y)/sin(x+y)= (tanx−tany)/(tanx+tany)`

Prove that (sin (x +y) )/( sin (x-y)) = (tan x + tan y)/( tan x - tan y).

Find (dy)/(dx) where y=(tanx)/(x)

Show that sin(x+y)sin(x-y)= sin^2 x -sin^2 y .Hence prove that sin(x+y)sin(x-y)+sin(y+z)sin(y-z) +sin(z+x)sin(z-x)=0

If cos ( xy) = x , show that (dy)/(dx) = -((1+ y sin (xy)))/(x sin xy)

If y=(tanx)/(x) find (dy)/(dx)

IF ( sin ( x+y) )/( sin (x-y) ) = (a+b)/( a-b) , then ( tan x)/( tan y) =

Show that ( sin x + sin y) /( cos x + cos y) = tan ""(x+y)/(2)

prove that (sin x-sin y)/(cos x+cos y) = tan "" ( x-y)/(2)

If (sin (A+B))/( sin (A-B )) = (x+y)/(x-y) , then x/y