Use this:
1)
2)
3)
How do I solve:
Using Double Angle identities
1. (2 tan 15) / (1 - tan^2 15)
2. sin(pi/6)cos(pi/6)
3. cos^2 (2x) - sin^2 (2x)
Answers:
1. [sq.root(3)] / 3
2. [sq.root(3)] / 4
3. cos 4x
Thank you very much for your time! =)