Question

Hi, can you answer the second question for me (number 4)?

Answer 1

4.

`\begin{gathered} (cos\theta)/(1+sin\theta)+(cos\theta)/(1-sin\theta)=(cos\theta(1-sin\theta)+cos\theta(1+sin\theta))/((1+sin\theta)(1-sin\theta)) \\ \\ (cos\theta)/(1+sin\theta)+(cos\theta)/(1-sin\theta)=(cos\theta-sin\theta cos\theta+cos\theta+sin\theta cos\theta)/(1-sin^2\theta) \\ \\ (cos\theta)/(1+sin\theta)+(cos\theta)/(1-sin\theta)=(2cos\theta)/(cos^2\theta) \\ \\ (cos\theta)/(1+sin\theta)+(cos\theta)/(1-sin\theta)=(2)/(cos\theta) \\ \\ (cos\theta)/(1+sin\theta)+(cos\theta)/(1-sin\theta)=2sec\theta \end{gathered}`