`If 13theta =pi " show that"cos 3 theta + cos 5 theta + 2 cos theta cos 9theta = 0`

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

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

if 13theta=pi ,then show that cos3theta+cos5theta+2costheta.cos9theta=0

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

(sin 3 theta + sin 5 theta + sin 7 theta + sin 9theta)/(cos 3 theta + cos 5 theta + cos 7 theta + cos 9 theta )=

(sin 3 theta + sin 5 theta + sin 7 theta + sin 9theta)/(cos 3 theta + cos 5 theta + cos 7 theta + cos 9 theta )=

If cos theta + cos 2theta + cos 3theta = 0 then theta =

2 cos theta - cos 3 theta - cos 5 theta - 16 cos^(3) theta sin^(2) theta =

( sin 3 theta + sin 5 theta + sin 7 theta + sin 9 theta)/( cos 3 theta + cos 5 theta + cos 7 theta + cos 9 theta) is equal to

If theta=(pi)/(9), prove that cos theta cos2 theta cos3 theta cos4 theta=(1)/(16)