This ques has been taken from the Book Book- ML Aggarwal
Chapter- Trigonometric Identities
This is an important question and asked in previous exams.
(i) (1+cos theta -sin^2 theta) / sin theta (1 + cos theta ) = cot theta. (ii)tan³ theta- 1 / tan theta -1 = sec² theta+ tan theta
Class 10, chapter 18, ML aggarwal, trigonometric identities, question no 21