If `(a+b) tan(theta-phi)=(a-b)tan(theta+phi)` and `a cos2phi+bcos2theta=c` , then prove that `a^2-b^2+c^2=2ac cos2phi`

If (a+b)tan(theta-phi)=(a-b)tan(theta+phi) and a cos2 phi+b cos2 theta=c then prove that a^(2)-b^(2)+c^(2)=2ac cos2 phi

If (a+b)tan(theta-phi)=(a-b)tan(theta-phi) and acos2phi+bcos2theta=c show that a^2-b^2+c^2=2a cos2phi

If (a + b) tan (theta - phi) = (a-b) tan (theta + phi) " and " a cos 2 phi + b cos 2 theta = c, "show that" a^(2) -b^(2) + c^(2) = 2a cos 2 phi

(a+b)tan(theta-phi)=(a-b)tan(theta+phi) then (sin 2theta)/(sin 2phi)=

If (a-b)sin (theta+phi)=(a+b)sin(theta-phi) and a tan. (theta)/(2)-b tan.(phi)/(2)=c , then

If tan^(2)theta=1+2tan^(2)phi, prove that cos2 phi=1+2cos2 theta

If sin theta - sin phi = a and cos theta + cos phi = b then prove that cos(theta + phi) = (a^(2)+b^(2) -2)/2

If tan^2 theta = 1+2 tan^2 phi , prove that cos 2 phi = 1 + 2 cos 2 theta .

Prove that, cos^(2) (theta + phi) - sin^(2) (theta - phi) = cos 2 theta cos 2 phi