" 4.If "sin alpha+sin beta=a" and "cos alpha+cos beta=b" then "

If sin alpha + sin beta = a " and " cos alpha + cos beta = b then proved that cos(alpha - beta) = (a^(2) + b^(2) - 2)/(2) " and " tan ""(alpha - beta)/(2) = pm sqrt (4-a^(2)-b^(2))/(a^(2)+b^(2)) .

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 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 sin alpha + sin beta = a , cos alpha + cos beta = b " then sin ( alpha + beta ) =

If sin alpha + sin beta = a , cos alpha + cos beta = b " then cos ( alpha + beta ) =

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