Double and Half Angles

• Oct 20th 2008, 04:26 PM
Double and Half Angles
For http://webwork.math.wvu.edu/webwork2...1451f60671.png use a double-angle or half-angle formula to simplify the equation and then find all solutions of the equation in the interval http://webwork.math.wvu.edu/webwork2...496bd8b181.png

x=_________pi
• Oct 20th 2008, 05:54 PM
Krizalid
Well, then use it, hence $2\sin x\cos x+\cos x=\cos x(2\sin x+1)=0,$ from here $\cos x=0$ or $2\sin x+1=0.$ Each one can be easily solved, do it.