Prove that `cos (2theta) /(1+sin 2 theta)=tan(pi/4-theta)`

Prove that cos theta/(1-sin theta)=tan (pi/4+theta/2)

Prove that (1+cos theta)/(sin theta)=(1+sin theta+cos theta)/(1+sin theta-cos theta) .

Prove that cos((phi-theta)/2)-sinthetasin((phi+theta)/2)=costhetacos((phi+theta)/2)

Prove that cos^2(pi/4-theta)-sin^2(pi/4-theta)=sin 2theta

Solve 2cos^2 theta+3 sin theta=0

Find cos^2 theta - sin^2 theta . .

Prove that (((1+cot theta +tan theta)(sintheta-costheta))/(sec^3theta -cosec^3theta)) = (sin^2theta cos^2theta)

If cos theta+sin theta=sqrt 2 cos theta ,then prove that cos theta-sin theta = sqrt 2 sin theta .

Solve 7 cos^2 theta+3 sin^2 theta=4

Prove that 8 sin^4(theta/2)-8sin^2(theta/2)+1=cos2theta