`sin(x+y) cos(x-y) + cos(x+y) sin(x-y)`=

cos (x + y), sin (x + y), - cos (x + y) sin (xy), cos (xy), sin (xy) sin2x, 0, sin2y] | = sin2 (x + y)

What is the value of {sin (x+y) -2 sin x+ sin(x-y)} /[cos (x-y) +cos (x+ y)-2 cos x] xx [(sin 10x- sin 8x)/ (cos-10x + cos 8x)] ? {[sin (x+y] -2 sin x+ sin(x-y)}//[cos (x-y) +cos (x+ y)-2 cos x]} xx [(sin 10x-sin 8x)//(cos10x + cos 8x)] का मान क्या है?

prove that: cos ^ (2) x + cos ^ (2) y-2cos x * cos y * cos (x + y) = sin ^ (2) (x + y)

[x (cos y) / (x) + y (sin y) / (x)] y = [y (sin y) / (x) -x (cos y) / (x)] x ((dy) / (dx))

cos4x-cos4y = 8 (cos x-cos y) (cos x + cos y) (cos x-sin y) (cos x + sin y)

[x cos (y / x) + y sin (y / x)] y- [y sin (y / x) -x cos (y / x)] x (dy) / (dx) = 0

Prove the following Identities (sin(x+y)-2sinx+sin(x-y))/(cos(x+y)-2cosx+cos(x-y))=tanx

Prove that : (sin (x+y))/(sin (x-y) )= (sin x. cos y + cos x . Sin y)/(sin x. cos y-cos x. sin y)