\begin{array}{l}{\frac{\cos ^{2} \theta}{\sin \theta}+\sin \theta=\csc \theta} \\ {\frac{1-\sin \theta}{1+\sin \theta}=(\sec \theta+\tan \theta)^{2}} \\ {\frac{1-\cos \theta}{1+\cos \theta}=(\cot \theta-\csc \theta)^{2}}\end{array}

\begin{array}{l}{\frac{\cos ^{2} \theta}{\sin \theta}+\sin \theta=\csc

1.	\begin{array}{l}{\frac{\cos ^{2} \theta}{\sin \theta}+\sin \theta=\csc \theta} \\ {\frac{1-\sin \theta}{1+\sin \theta}=(\sec \theta+\tan \theta)^{2}} \\ {\frac{1-\cos \theta}{1+\cos \theta}=(\cot \theta-\csc \theta)^{2}}\end{array}
Answer» 26)(costcost+sintsint)/sint=1/sint=cosect27)(1-sint)/(1+sint) =((1-sint)(1-sint)/(1+sint)(1-sint)) =(1-2sint+sintsint)/(1-sintsint) =(1-2sint+sintsint)/(costcost) =sectsect-2secttant+tanttant =(sect+tant)(sect+tant)28)(1-cost)/(1+cost) =((1-cost)(1-cost)/(1+cost)(1-cost)) =(1-2cost+costcost)/(1-costcost) =(1-2cost+costcost)/(sintsint) =(cosectcosect-2cosectcott+cottcott) =(cosect-cott)(cosect-cott)