If `sin alpha + sin beta = a and cos alpha + cos beta =b`, show that `sin(alpha+beta)=(2ab)/(alpha^2+beta^2)`

If s in alpha+s in beta=a and cos alpha+cos beta=b show that: sin(alpha+beta)=(2ab)/(a^(2)+b^(2))cos(alpha+beta)=(b^(2)-a^(2))/(b^(2)+a^(2))

If sin alpha + sin beta = a and cos alpha + cos beta = b, prove that : cos (alpha-beta) = 1/2 (a^2 + b^2 -2)

If sin alpha+sin beta=a and cos alpha+cos beta=b prove that :cos(alpha-beta)=(1)/(2)(a^(2)+b^(2)-2)

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

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

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

If cos alpha+ cos beta= a and sin alpha+ sin beta =b , then show that sin 2 alpha+ sin 2 beta =2 ab(1- (2)/(a^(2)+ b^(2))) .

(cos alpha + cos beta) ^ (2) + (sin alpha + sin beta) ^ (2) =