This is an important question from the
Book- ML Aggarwal
Chapter- Trigonometric Identities
We have to prove that equality
(i) (sin θ + cos θ) (sec θ + cosec θ) = 2 + sec θ cosec θ (ii) (cosec A – sin A) (sec A – cos A) sec2A = tan A
Trigonometric Identities, class 10th, chapter 18th, question no 28, ICSE board, ML aggarwal..