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

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

Prove that (1+costheta-sin^(2)theta)/(sintheta(1+costheta))=cottheta

Prove that : (sintheta-2sin^(3)theta)/(2cos^(3)theta-costheta)-tantheta

Prove that: (1+sintheta-costheta)/(1+sintheta+costheta)=tan(theta/2)

Solve: costheta+cos3theta+cos5theta+cos7theta=0

Prove that tantheta=(sintheta-2sin^3theta)/(2cos^3theta-costheta)

Prove that sin^(3)theta+cos^(3)theta=(sintheta+costheta)(1-sin thetacostheta) .

Prove that ("cosec "theta-sintheta)(sectheta-costheta)(tantheta+cottheta)=1

Prove that : (1+costheta- sin^(2)theta)/(sintheta+sinthetacostheta)=cottheta

Prove that : (sintheta)/(1+costheta)+(1+costheta)/(sintheta)=2"cosec"theta