cos(theta+gamma)=7cos(theta-phi)quad " then fhed "

If cos(theta+phi)=m cos(theta-phi) then tan theta is equal to

If cos(theta-phi) , cos(theta) , cos(theta+phi) are in HP, the the value of cos(theta)sec(phi/2) is

If cos(theta-phi),cos(theta),cos(theta+phi) are in HP, the the value of cos(theta)sec((phi)/(2)) is

If a=costheta+isintheta, b=cos phi+isinphi ,find the values of cos(theta+phi) and cos(theta-phi) in terms of a and b.

(sin (theta+phi) -2 sintheta+ sin (theta-phi))/( cos(theta+phi) -2 costheta+ cos (theta-phi))= tan theta

prove that (cos3 theta+cos3 phi)/(2cos(theta+phi)-1)=(cos theta+cos phi)cos(theta+phi)-(sin theta+sin phi)sin(theta+phi)

(sin(theta+phi)-2sin theta+sin(theta-phi))/(cos(theta+phi)-2cos theta+cos(theta-phi))=tan theta

If alpha + beta + gamma = 2 theta , " then " cos theta + cos ( theta - alpha ) + cos (theta - beta ) + cos ( theta - gamma ) =

If alpha+beta+gamma=2 theta ,then cos theta + cos(theta - alpha) + cos(theta - beta) + cos(theta - gamma) =

cos 2 (theta+ phi) +4 cos (theta + phi ) sin theta sin phi + 2 sin ^(2) phi=