Trigonometrymedium · Past Paper
Simplify: (cos A - sin A)(cos A + sin A).
A1
Bcos 2A
Csin 2A
D0
✓ Correct Answer: B — cos 2A
The product is cos² A - sin² A, which is the formula for cos 2A.
Share this question
More from Trigonometry
- Which of the following is equal to cos 90 degrees?
- If the height of a pole is increased by 10%, and the angle of elevation remains 45°, the shadow length:
- What is the value of tan 30 / cot 60?
- Find the value of (1 + cot A - cosec A)(1 + tan A + sec A).
- If sin θ + cosec θ = 2, then find sinⁿ θ + cosecⁿ θ.