[cos4 alpha*cos5 alpha*cos0 alphaquad 16],[" 92.If tanA "tan B=sqrt((a-b)/(a+b))" ,prove that "(a-b)],[cos2A)(a-b cos2B)=a^(2)-b^(2)]

If tan A tan B=sqrt((a-b)/(a+b)), prove that (a-b cos2A)(a-b cos2B)=a^(2)-b^(2)

If tan A tan B=sqrt((a-b)/(a+b)) show that (a-b cos2A)(a-b cos2B)=a^(2)-b^(2)

If 3tanA tanB=1 , then prove that 2cos(A+B)=cos(A-B)

If tan(theta)/(2)=sqrt((a-b)/(a+b))tan(phi)/(2), prove that cos theta=(a cos phi+b)/(a+b cos phi)

If sin(theta+alpha)=a and sin(theta+beta)=b, prove that cos2(alpha-beta)-4ab cos(alpha-beta)=1-2a^(2)-2b^(2)

If cos theta=(a cos alpha+b)/(a+b cos alpha), then the value of tan((theta)/(2)) is :

If alpha and beta are the two different roots of equations alpha cos theta+b sin theta=c , prove that (a) tan (alpha-beta)=(2ab)/(a^(2)-b^(2)) (b) cos(alpha+beta)=(a^(2)-b^(2))/(a^(2)+b^(2))

If alpha and beta are the two different roots of equations alpha cos theta+b sin theta=c , prove that (a) tan (alpha-beta)=(2ab)/(a^(2)-b^(2)) (b) cos(alpha+beta)=(a^(2)-b^(2))/(a^(2)+b^(2))

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

Prove that 2 tan ^(-1)[(sqrt((a-b)/(a+b))) tan ((theta)/2)]=cos ^(-1)((b+a cos theta)/(a+b cos theta))