" Q16.If "(cos alpha)/(cos beta)=m" and "(cos alpha)/(sin beta)=n;" show that "-(m^(2)+n^(2))cos^(2)beta=n^(2)

If n=(cos alpha)/(cos beta),m=(sin alpha)/(sin beta) then (m^(2)-n^(2))sin^(2)beta is

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

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

If cos alpha+cos beta=0=sin alpha+sin beta then cos2 alpha+cos2 beta=

If (cos^(4)alpha)/(cos^(2) beta) + (sin^(4)alpha)/(sin^(2)beta) = 1, prove that (cos^(4)beta)/(cos^(2) alpha) + (sin^(4)beta)/(sin^(2)alpha)= 1

If (cos^4 alpha)/(cos^2beta)+(sin^4alpha)/(sin^2beta)=1 ,then prove that (cos^4beta)/(cos^2alpha)+(sin^4beta)/(sin^2alpha)=1

(cos alpha + cos beta) ^ (2) + (sin alpha-sin beta) ^ (2) = 4 (cos ^ (2) (alpha + beta)) / (2)

If (cos^(4)alpha)/(cos^(2)beta)+(sin^(4)alpha)/(sin^(2)beta)=1, then provet that (cos^(4)beta)/(cos^(2)alpha)+(sin^(4)beta)/(sin^(2)alpha)=1.