Prove that, `1/(costheta-cos3theta)+1/(costheta-cos5theta)+1/(costheta-cos7theta)+…+to n terms = 1/(2sintheta) [cottheta-cot(n+1)theta]`

(sin3theta-cos3theta)/(sintheta+costheta)+1 =

(sintheta+sin2theta)/(1+costheta+cos2theta) =

int(costheta-cos2theta)/(1-cos theta)d theta=

Prove that: (sin2theta)/(costheta cos3theta)+(sin4theta)/(cos3theta.cos5theta)+(sin6theta)/(cos5theta.cos7theta)+… to terms = 1/(2sintheta) [sec(2n+1)theta-sectheta]

costheta.cos2theta.cos3theta=1/4

Prove that sqrt((cosec theta+cottheta)/(cosec theta-cottheta))=(sin theta)/(1-costheta)

(sintheta+sin2theta)/(1+costheta+cos2theta)=?

Prove that sintheta/(1-costheta)=cosectheta+cot theta

Prove (sin^3theta+cos^3theta)/(sintheta+costheta)=1-sinthetacostheta

Solve: costheta+cos3theta+cos5theta+cos7theta=0