`1+cos2theta+cos4theta+cos6theta=`

4cos6 theta cos4 theta cos2 theta=

If 13 theta =pi , " prove that " cos theta cos 2theta cos3 theta cos4theta cos5 theta cos6 theta =1/2^(6)

Prove that, If " "15 theta = pi, "show that," cos theta cos2 theta cos3theta cos 4theta cos5 theta cos6theta cos7theta =1/2^(7)

If 13theta=pi ,show that costhetacos2theta cos3theta cos4theta cos5theta cos6theta=2^-6

cos 3theta+cos 5theta+cos 7theta+cos 9theta=4 cos theta cos 2theta cos 6theta .

If m and n are positive integers satisfying 1+cos2 theta+cos4 theta+cos6 theta+cos8 theta+cos10 theta=(cos m theta*sin n theta)/(sin theta) then (m+n) is equal to

Prove the following : cos 3 theta+ cos 5 theta+ cos 7 theta+ cos 9 theta= 4 cos theta cos 2 theta cos 6 theta .

If cos theta cos 2 theta cos 3theta = 1//4 for 0 lt theta lt pi then theta =

1+ cos 2 theta + cos 4 theta + cos 6 theta =