1.In a △ ABC, right-angled at B, AB = 24 cm , BC = 7 cm. Determine
(i) sin A , cos A (ii) sin C, cos C. Ans : 7/25&24/25. Ans : 24/25&7/25
2.If tanθ=a/b,find the value of (cos θ + sin θ)/ (cos θ – sin θ). Ans : (a+b)/(a-b)
3. In △PQR, right-angled at Q, PQ = 4cm and RQ = 3 cm. Find the value of
sinP, sin R, sec P and sec R. Ans: 3/5 , 4/5, 5/4&5/3
4. sin2 30∘ + sin2 45∘ + sin2 60∘ + sin2 90°. Ans:5/2
5. 4(sin4 60∘ + cos4 30∘) − 3(tan2 60∘ − tan2 45∘) + 5cos2 45°. Ans :1
6. 4(sin4 30∘ + cos2 60∘) − 3(cos2 45∘ − sin2 90∘) − sin2 60° Ans : 2
7. cos θ/ (1 – sin θ) = (1 + sin θ)/ cos θ
8. cos θ/ (1 + sin θ) = (1 – sin θ)/ cos θ
9. (1 – sin θ) / (1 + sin θ) = (sec θ – tan θ)^2
10.
11. 1 – cos θ/ sin θ = sin θ/ 1 + cos θ
12.
13. tan2 θ − sin2 θ = tan2 θ sin2 θ
14. (cosec θ + sin θ)(cosec θ – sin θ) = cot2θ + cos2θ
15. cosec (A – sin A)(sec A – cos A)(tan A + cot A) = 1
16. sec A(1- sin A) (sec A + tan A) = 1
17. (sec θ + cos θ) (sec θ – cos θ) = tan2 θ + sin2 θ
18. (1 + tan2 θ)(1 – sin θ)(1 + sin θ) = 1
(i) sin A , cos A (ii) sin C, cos C. Ans : 7/25&24/25. Ans : 24/25&7/25
2.If tanθ=a/b,find the value of (cos θ + sin θ)/ (cos θ – sin θ). Ans : (a+b)/(a-b)
3. In △PQR, right-angled at Q, PQ = 4cm and RQ = 3 cm. Find the value of
sinP, sin R, sec P and sec R. Ans: 3/5 , 4/5, 5/4&5/3
4. sin2 30∘ + sin2 45∘ + sin2 60∘ + sin2 90°. Ans:5/2
5. 4(sin4 60∘ + cos4 30∘) − 3(tan2 60∘ − tan2 45∘) + 5cos2 45°. Ans :1
6. 4(sin4 30∘ + cos2 60∘) − 3(cos2 45∘ − sin2 90∘) − sin2 60° Ans : 2
7. cos θ/ (1 – sin θ) = (1 + sin θ)/ cos θ
8. cos θ/ (1 + sin θ) = (1 – sin θ)/ cos θ
9. (1 – sin θ) / (1 + sin θ) = (sec θ – tan θ)^2
10.
11. 1 – cos θ/ sin θ = sin θ/ 1 + cos θ
12.
13. tan2 θ − sin2 θ = tan2 θ sin2 θ
14. (cosec θ + sin θ)(cosec θ – sin θ) = cot2θ + cos2θ
15. cosec (A – sin A)(sec A – cos A)(tan A + cot A) = 1
16. sec A(1- sin A) (sec A + tan A) = 1
17. (sec θ + cos θ) (sec θ – cos θ) = tan2 θ + sin2 θ
18. (1 + tan2 θ)(1 – sin θ)(1 + sin θ) = 1