(sin A + cos A)(sec A + cosec A) = 2 + sec A cosec A

(tan A + cot A)(cosec A - sin A)(sec A - cos A) = 1

If 4 cos² A - 3 = 0 and 0° ≤ A ≤ 90°; then prove that :

(i) sin 3A = 3 sin A - 4 sin³ A

(ii) cos 3A = 4 cos³ A - 3 cos A