I am having trouble

Question

1-sin/cos=cos/1+sin

Answer 1

cosθ/(1+sinθ) = [cosθ(1-sinθ)]/[(1+sinθ)(1-sinθ)]

 

                    = [cosθ(1-sinθ)]/[1-sin²θ]

 

                    = [cosθ(1-sinθ)]/cos²θ

 

                    = (1-sinθ)/cosθ

Answer 2

cross multiply

cos²=(1-sin)(1+sin)

cos²=1-sin²

sin²+cos²=1 trig identity