(1 + sin A)(1 − sin A) is equal to:

1. cosec²A

2. sin²A

3. sec²A

4. cos²A

(cos⁴ θ − sin⁴ θ) is equal to :

1. 2 cos² θ + 1

2. 2 cos² θ − 1

3. 2 sin² θ + 1

4. 2 sin² θ − 1