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

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

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 tan((alpha-beta)/(2))=+-sqrt((4-a^(2)-b^(2))/(a^(2)+b^(2)))

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

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 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) is equal to-