`costheta+cos2theta+cos3theta+.......+cos(n-1)theta+cosntheta=`

If (2^n+1)theta=pi then 2^n costheta cos2theta cos2^2 theta .......cos 2^(n-1) theta=

For all n in N, cos theta cos 2theta cos 4theta ....cos2^(n-1)theta equals to

If (costheta +isintheta)(cos2theta +isin2theta).....(cosntheta + isinntheta) = 1 then the value of theta is:

Prove that ( cos theta + cos 2 theta + cos 3 theta + cos 4 theta)/(sin theta + sin 2 theta + sin 3 theta + sin 4 theta)= cot ""(5theta)/(2).

Prove (cos 3theta+ 2 cos 5theta+ cos 7theta)/( cos theta+ 2 cos 3theta+ cos 5theta)= cos 2theta- sin 2theta tan 3theta .

Prove that: (cos6theta+6cos4theta+15 cos2theta+10)/(cos5theta+5cos3theta+10 costheta)=2costheta

Prove that cos theta cos 2 theta cos 4 theta…. Cos 2 ^(n-1) theta = ( sin ( 2 ^(n) theta))/( 2 ^(n) (sin theta)) .

Solve: cos3theta+costheta=0

Find the sum of the series costheta.cos2theta+cos3theta.cos4theta+cos5theta.cos6theta+…to n terms

If theta = (pi)/(2 ^(n) +1) prove that 2 ^(n) cos theta cos 2 theta cos 2 ^(2) theta…. Cos 2 ^(n -1) theta =1