If `cos x -sin alpha cot beta sin x=cos alpha` then the value of tan`x/2` is

If cos x-sin alpha cot beta sin x=cos a, then the value of tan((x)/(2)) is (a)-tan((alpha)/(2))cot((beta)/(2)) (b) tan((alpha)/(2))tan((beta)/(2))(c)-cot((alpha beta)/(2))tan((beta)/(2))(d)cot((alpha)/(2))cot((beta)/(2))

If sin alpha sin beta-cos alpha cos beta+1=0, then the value of 1+cot alpha tan beta is

If cos alpha + cos beta = 0 = sin alpha + sin beta, then value of cos 2 alpha + cos 2 beta is

If sin alpha-sin beta=a and cos alpha+cos beta=b then write the value of cos(alpha+beta)

If sin alpha-sin beta=a and cos alpha+cos beta=b then write the value of cos(alpha+beta)

If alpha,beta and gamma are angles such that tan alpha+tan beta+tan gamma=tan alpha tan beta tan gamma and x=cos alpha+i sin alpha,y=cos beta+i sin beta and z=cos gamma+i sin gamma then the value of xyz is

If sin alpha+sin beta=a and cos alpha+cos beta=b then tan((alpha-beta)/(2)) is equal to