If `sin x + sin y =a` and `cos x + cos y = b`,then tan((x + y)/2` is equal to

If sin x + sin y = 1/2 and cos x + cos y = 1 then tan (x + y)

If sin x + sin y = a and cos x + cos y = b, than tan^2((x+y)/(2))+tan^2((x-y)/(2)) is equal to:

If sin x + sin y = a , cos x - cos y = b then the value of tan ((y-x)/2) is _______ in terms of a and b.

If sin x + sin y= (1)/(2) and cos x + cos y=1 , then tan (x+y) =______

If sin x+sin y=a and cos x+cos y=b then thevalue of sin(x+y) is

If sin x+sin y=a and cos x+cos y=b then cos(x-y) is equal to (1)/(2)(a^(2)+b^(2)-2)(B)(1)/(2)(a^(2)+b^(2)+2)

If sin x + sin y = a, cos x + cos y = b, then what is the value of cos (x-y) ?