f_(1)-sin theta-cos theta^(2)=2(1+sin theta)(1+cos theta)

((sin theta+cos theta)^(2)-1)/(sin theta*cos theta)

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

Prove that (1-sin theta+cos theta)^(2)=2(1+cos theta)(1-sin theta)

(1 + sin theta-cos theta) / (1 + sin theta + cos theta)

(sin theta-cos theta+1)/(sin theta+cos theta-1)=(1+sin theta)/(cos theta)

prove that (cos theta)/(1-sin theta)+(cos theta)/(1+sin theta)=(2)/(cos theta)

(1+ sin theta - cos theta )/( 1+ sin theta + cos theta ) + (1+ sin theta + cos theta )/( 1+ sin theta - cos theta ) =

((1 + sin theta-cos theta) / (1 + sin theta + cos theta)) ^ (2) = (1-cos theta) / (1 + cos theta)

(xv) (cos^2 theta) / (1- tan theta) +( sin^3 theta)/ (sin theta - cos theta) = 1 + sin theta cos theta

Prove : (cos^2 theta)/(1-tan theta) + (sin^3 theta)/(sin theta-cos theta) = 1 + sin theta cos theta