Assertion (A): cosec² 54° - cot² 54° = 1.

Reason (R): cosec² θ - cot² θ = 1 for all values of θ, 0° < θ ≤ 90°.

1. Assertion (A) is true, Reason (R) is false.

2. Assertion (A) is false, Reason (R) is true.

3. Both Assertion (A) and Reason (R) are correct, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are correct, and Reason (R) is incorrect reason for Assertion (A).

Assertion (A): 1 + sec² θ = tan² θ is a trigonometric identity.

Reason (R): An equation involving trigonometric ratio of an angle is called trigonometric identity if it is true for all values of the angles involved.

1. Assertion (A) is true, Reason (R) is false.

2. Assertion (A) is false, Reason (R) is true.

3. Both Assertion (A) and Reason (R) are correct, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are correct, and Reason (R) is incorrect reason for Assertion (A).

If θ is an acute angle and tan θ = $\dfrac{8}{15}$, find the value of sec θ + cosec θ.

Evaluate the following :

$2 \times \Big(\dfrac{\text{cos}^2 20° + \text{cos}^2 70°}{\text{sin}^2 25° + \text{sin}^2 65°}\Big)$ - tan 45° + tan 13° tan 23° tan 30° tan 67° tan 77°