This ques is from ML Aggarwal book, Avichal publication, class 10th.
Chapter 18, trigonometric identities
Express the ratios cos A, tan A and sec A in terms of sin A
Provde the solution with mentioning identities, wherever applied.
Class10, ML Aggarwal, trigonometric identities, ques no. 3
We know that,
sin²A + cos² A = 1
So,
cos A = √(1 – sin² A)
tan A = sin A/cos A = sin A/ √(1 – sin² A)
sec A = 1/cos A = 1/ (√1 – sin² A)