Section A: Basic Conceptual Questions
- Define trigonometry.
- Write the values of sin 0°, sin 30°, sin 45°, sin 60°, sin 90°.
- Write the values of cos 0°, cos 30°, cos 45°, cos 60°, cos 90°.
- Write the values of tan 0°, tan 30°, tan 45°, tan 60°.
- What is the relation between sin θ and cos (90° − θ)?
- What is the value of sin²θ + cos²θ?
- Define complementary angles in trigonometry.
- What is the value of tan 45° × tan 30° × tan 60°?
Section B: Evaluate the following
- sin 30° + cos 60°
- sin 45° − cos 45°
- tan 60° − tan 30°
- sin 60° × cos 30°
- cos 45° × cos 45°
- tan 30° × tan 60°
- sin 90° × cos 0°
- sin 30° × sin 60° × sin 45°
Section C: Simplification
- sin²30° + cos²30°
- sin²45° + cos²45°
- 1 + tan²45°
- 1 + tan²30° − sec²30°
- (sin 60° / cos 30°)
- (cos 60° / sin 30°)
- (tan 45° + tan 30°)
- (sin 60° − cos 30°)
Section D: Verify Identities
- sin²θ + cos²θ = 1
- 1 + tan²θ = sec²θ
- 1 + cot²θ = cosec²θ
- sin θ / cos θ = tan θ
- (sec θ × cos θ) = 1
- (cosec θ × sin θ) = 1
Section E: Word Problems
- A ladder is inclined at 60° to the ground and its foot is 5 m away from the wall. Find its height.
- A tree casts a shadow of 10 m when the sun’s elevation is 45°. Find the height of the tree.
- A kite is flying at a height of 50 m with string making 30° angle with ground. Find length of string.
- A tower is 40 m high. Find angle of elevation from a point 40 m away.
- A person observes top of a building at 60° angle. Distance is 20 m. Find height of building.
Section F: Higher Order Thinking (HOTS)
- If sin θ = 3/5, find cos θ and tan θ.
- If cos θ = 12/13, find sin θ and tan θ.
- If tan θ = 1, find sin θ and cos θ.
- Prove that (sin θ + cos θ)² = 1 + 2sin θ cos θ
- Show that (sec θ − tan θ)(sec θ + tan θ) = 1
Answer Key (Short Answers)
- Study of relationships between angles and sides of triangles
- 0, 1/2, 1/√2, √3/2, 1
- 1, √3/2, 1/√2, 1/2, 0
- 0, 1/√3, 1, √3
- sin θ = cos(90° − θ)
- 1
- Angles that add to 90°
- 1
- 1
- 0
- √3 − 1/√3
- 3/4
- 1/2
- 1
- 1
- 3/8
17–19. 1
20. 0
21. √3
22. 1
23. 1 + 1/√3
24. 0
25–30. True identities
- 5√3 m
- 10 m
- 100 m
- 40 m
- 20√3 m
- 4/5, 3/5, 3/4
- 5/13, 5/12, 5/12
- 1/√2, 1/√2
39–40. Verified identities