Prove that `(cos theta-sintheta)/(cos theta+sintheta)=sec 2 theta-tan 2theta`.

Prove that (1- cos theta + sin theta)/( 1+cos theta +sin theta) = "tan"(theta)/(2) .

Prove that (sintheta-costheta+1)/(sintheta+costheta-1)=1/(sectheta-tantheta) , using the identity sec^2theta=1+tan^2theta

Prove that : (sintheta +sin2theta)/(1+costheta+cos2theta)=tantheta

Prove: (cos^2theta)/(sintheta)-cos e c\ theta+sintheta=0

Prove : (cos theta)/(1+sin theta) + (cos theta)/(1-sin theta)= 2 sec theta

Prove: (cos e c\ theta+sintheta)(cos e c\ theta-sintheta)=cot^2theta+cos^2theta

Prove that : (sin^(2)theta)/(cos theta)+cos theta=sec theta

Prove that (sin theta- "cosec" theta )(cos theta- sec theta )=(1)/(tan theta + cot theta).

Prove that, 1/(costheta-cos3theta)+1/(costheta-cos5theta)+1/(costheta-cos7theta)+…+to n terms = 1/(2sintheta) [cottheta-cot(n+1)theta]

Prove that: sqrt((1-sintheta)/(1+sintheta))= sec theta- tan theta when (-pi/2) < theta < pi/2 and -sec theta+tan theta when pi/2< theta< (3pi)/2