Question

1+cos 2A / 1- cos 2A = tan^2 A​

Answer 1

LHS.

1 - cos 2A / 1+cos2A.

1 - (1- 2 Sin²A) / 1 + 2cos²A-1.

2 Sin²A / 2 cos² A.

sin²A / cos²A.

tan² A. hence proved.