" If "cos x=3cos y," then "2tan(y-x)/(2)=

If cos x=3 cos y, then 2 tan ((y-x)/(2))= ............. A) cot ((y-x)/(2)) B) cot ((x+y)/(4)) C) cot ((y-x)/(4)) D) cot ((x+y)/(2))

If sinx + 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 tan((x+y)/2 ' is equal to

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:

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

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

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