Question

Prove that cosA/ (1-sinA) +cosA/ (1+sinA) =2secA

Answer 1

Answer:

cosA/(1-sinA)+cosA/(1+sinA)=LHS

cosA + cosA/(1-sinA)(1+sinA)

2cosA/1^2-sinA^2. [1^2-sinA^2=cos^2A]

2cosA/cos^2A

2×1/cosA. [1/cosA=secA]

2secA=RHS