This is the basic and exam oriented question as it is already asked in previous year paper of 2007 in which we have to prove that (sinθ+cosθ)/(sinθ-cosθ) + (sinθ-cosθ)/(sinθ+cosθ) = 2/(sin²θ-cos²θ) = 2/(2sin²θ-1)
RS Aggarwal, class 10, chapter 13A, question no 29