Prove that :
`Sintheta = Cos( pi/2 - theta )`

Prove that: 2cos theta cos((pi)/(3)+theta)cos((pi)/(3)-theta)=cos3 theta

Prove that sintheta (1 + Costheta) is the greatest at theta=pi/3

Prove that lim_(theta rarr(pi)/(2))(2cos theta)/(pi-2 theta)=1

Prove that: (cos(2 pi+theta)csc(2 pi+theta)tan(pi/2+theta))/(sec(pi/2+theta)cos theta cot(pi+theta))=1

If theta = pi/7 prove that cos theta* cos 2theta * cos 3theta = 1/8

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

Prove that (Sintheta)/(1+Costheta)+(1+Costheta)/(Sintheta)=2"Cosec"theta

Prove that: cos^(2)theta+cos^(2)((pi)/(3)+theta)+cos^(2)((pi)/(3)-theta)=(3)/(2)

If costheta +sin theta= sqrt(2)cos theta , then prove that costheta-sintheta =sqrt(2)sin theta

If theta=(pi)/(7), prove that cos theta cos2 theta cos3 theta=(1)/(2^(3))