cos3 theta cos5 theta-cos7 theta cos9 theta=0

(sin3 theta+sin5 theta+sin7 theta+sin9 theta)/(cos3 theta+cos5 theta+cos7 theta+cos9 theta)

(sin3 theta+sin5 theta+sin7 theta+sin9 theta)/(cos3 theta+cos5 theta+cos7 theta+cos9 theta) is equal to tan3 theta(b)cot3 theta(c)tan6 theta(d)cot6 theta

The value of the expression (sin3 theta+sin5 theta+sin7 theta+sin9 theta)/(cos3 theta+cos5 theta+cos7 theta+cos9 theta) when theta=(pi)/(18) is

(cos3 theta+2cos5 theta+cos7 theta)/(cos theta+2cos3 theta+cos5 theta)=cos2 theta-sin2 theta tan3 theta

prove that (sin theta-sin5 theta+sin9 theta-sin13 theta)/(cos theta-cos5 theta-cos9 theta+cos13 theta)=cot4 theta

Prove that (cos3 theta+2cos5 theta+cos7 theta)/(cos theta+2cos3 theta+cos5 theta)=cos2 theta-sin2 theta tan3 theta

(sin3theta+sin5theta+sin7theta+sin9theta)/(cos3theta+cos5theta+cos7theta+cos9theta)=

Solve :cos theta+cos3 theta+cos5 theta+cos7 theta=0

(sin3theta+sin5theta+sin7theta+sin9theta)/(cos3theta+cos5theta+cos7theta+cos9theta)=?

If cos theta+cos7 theta+cos3 theta+cos5 theta=0, then theta=