Trigonometryhard · Past Paper
Simplify: (cos A + sin A) / (cos A - sin A) - (cos A - sin A) / (cos A + sin A).
A2 tan 2A
B2 cot 2A
Ctan 2A
Dcot 2A
✓ Correct Answer: A — 2 tan 2A
Expression is ((cos+sin)² - (cos-sin)²) / (cos²-sin²) = (4 sin A cos A) / cos 2A = 2 sin 2A / cos 2A = 2 tan 2A.
Share this question
More from Trigonometry
- If tan A = x, then sin 2A is:
- In triangle ABC, tan A + tan B + tan C is equal to:
- Simplify: √( (1 - cos A) / (1 + cos A) ).
- A ladder 10 m long reaches a window 5 m high from the ground. Find the angle the ladder makes with the ground.
- From a lighthouse 100 m high, the angles of depression of two ships are 30° and 60°. If ships are on opposite sides, find distance between them.