Mohon dibantu ya kk. Buktikan identitas berikut. 1. Sin 2 alfa/ 1-cos 2 alfa = cot alfa 2. 1 - cos 2 theta/ 1 + cos 2 theta = tan² theta

1) sin 2a / 1-cos 2a
= 2.sin a cos a / 1 - (1 - 2.sin²a)
= 2.sin a cos a / 1 - 1 + 2.sin²a
= 2.sin a cos a / 2.sin²a
= cos a / sin a
= cot a
2) 1 - cos 2t / 1 + cos 2t
= 1 - (1 - 2.sin²t) / 1 + (2.cos²t - 1)
= 1 - 1 + 2.sin²t / 1 + 2.cos²t - 1
= 2.sin²t / 2.cos²t
= sin²t / cos²t
= tan²t