If `tan A tan B = sqrt((a-b)/(a+b)),` prove that : `(a-b cos 2A) (a-b cos 2B) = 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 tan theta tan phi=sqrt((a-b)/(a+b)) , prove that a-bcos 2theta)(a-b cos 2phi) is independent of theta and phi .

If tan theta.tan phi = sqrt ((a -b)/(a +b)), then (a -b cos 2 theta)(a -b cos 2 phi) is

tan theta.tan phi=sqrt((a-b)/(a+b)), then (a-b cos2 theta)(a-b cos2 phi)=

If tan theta =(a)/(b) prove that a sin 2theta + b cos 2theta =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 sqrt(a + b) tan = theta/2 = sqrt(a -b) tan phi/2 then prove that a + b cos phi = (a cos phi+ b) sec theta .

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

If 3tan A tan B=1, prove that 2cos(A+B)=cos(A-B)

If tan x=(a)/(b) then show that (a sin x-b cos x)/(a sin x+b cos x)=(a^(2)-b^(2))/(a^(2)+b^(2))