Activity-trigonometry problems

=Problem-1= prove that $$\frac{1-\tan^2 A}{1+\tan^2 A}=1-\sin^2 A$$

Interpretation of problems

 * 1) It is to prove the problem  based on trigonometric identities
 * 2) the function of one trigonometric ratio is relates to other

Concept development
Develop the skill of proving problem based trigonometric identity

Skill development
Problem solving