EXERCISE
1. In ∆ ABC, right-angled at B, AB = 24 cm, BC = 7 cm. Determine : (i) sin A, cos A (ii) sin C, cos C 2. In Fig., find tan P – cot R. 3. If sin A =$3/4$ ,calculate cos A and tan A. 4. Given 15 cot A = 8, find sin A and sec A. 5. Given sec θ = $13/12$, calculate all other trigonometric ratios. 6. If ∠ A and ∠ B are acute angles such that cos A = cos B, then show that ∠ A = ∠ B. 7. If cot θ = $7/8$, evaluate : (i) ${(1 + sin θ) (1 − sin θ)}/{(1 + cos θ)(1 − cos θ)}$ , (ii)cot2 θ 8. If 3 cot A = 4, check whether ${1 − tan^2 A}/{1 + tan^2A}$ = $cos^2A – sin^2A$ or not. 9. In triangle ABC, right-angled at B, if tan A = $1/√3$; find the value of: (i) sin A cos C + cos A sin C (ii) cos A cos C – sin A sin C 10. In ∆ PQR, right-angled at Q, PR + QR = 25 cm and PQ = 5 cm. Determine the values of sin P, cos P and tan P. 11. State whether the following are true or false. Justify your answer. (i) The value of tan A is always less than 1. (ii) sec A = $12/5$ for some value of angle A. (iii) cos A is the abbreviation used for the cosecant of angle A. (iv) cot A is the product of cot and A. (v) sin θ = $4/3$ for some angle θ.Solution