Calculate the value of A, if :

(tan A - 1) (cosec 3A - 1) = 0

(tan A - 1) (cosec 3A - 1) = 0

⇒ (tan A - 1) = 0 and (cosec 3A - 1) = 0

⇒ tan A = 1 and cosec 3A = 1

⇒ tan A = tan 45° and cosec 3A = cosec 90°

So, A = 45° and 3A = 90°

⇒ A = 45° and A = 30°

Hence, A = 45° and 30°.