18.(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))

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

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

Prove 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)

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

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)

" 1.If sin x+sin y=(1)/(4),cos x+cos y=(1)/(3) then tan((x+y)/(2))=

Show that (i) cos x+cos y=2 cos (x+y)/(2) cos (x-y)/(2) (ii) cos x-cos y=-2 sin (x+y)/(2) sin (x-y)/(2) (iii) sin x+sin y=2 sin (dot(x)+y)/(2) cos (x-y)/(2) (iv) sin x-sin y=2 cos (x+y)/(2) sin (x-y)/(2)