Sum to n terms the series `costheta-sin2theta-cos3theta+sin4theta+cos5theta-……`

Sum to terms of the series sintheta sin2theta + sin2thetasin3theta + sin3theta sin4theta +..... is equal to

Sum ot n terms the series sin^3theta+sin^3 3theta+sin^3 5 theta+…

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

Find the sum of n terms the series: 1/(costheta+cos3theta)+1/(costheta+cos5theta)+1/(costheta+cos7theta)+…

Solve: sin2theta+sin4theta=costheta+cos3theta

If the expression (sin theta sin2theta+sin3theta sin60theta+sin4theta sin13theta)/(sin theta cos 2theta+sin3theta cos 6theta+sin4theta cos13theta)=tan k theta , where k in N . Find the value of k.

Find the sum of n terms of the series sqrt(1-sin2theta)+(sqrt(1-sin4theta)+sqrt(1-sin6theta)+…

If f (theta) = [[cos^(2) theta , cos theta sin theta,-sin theta],[cos theta sin theta , sin^(2) theta , cos theta ],[sin theta ,-cos theta , 0]] ,then f ( pi / 7) is

sin^(3)theta + sin theta - sin theta cos^(2)theta =

Solve : 3-2 cos theta -4 sin theta - cos 2theta+sin 2theta=0 .