`sin alpha + sin beta = a "and" cos alpha + cos beta = b`
`cos (alpha + beta) =`

sin alpha + sin beta = a "and" cos alpha + cos beta = b sin (alpha + beta) =

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

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

sin alpha + sin beta = a, cos alpha + cos beta = b rArr sin (alpha + beta)

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

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

sin alpha + sin beta = 1/4 and cos alpha + cos beta = 1/3 The value of cos ( alpha + beta) is

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