Use a half-angle identity to find the exact value of tan 15°

Question

a. √ 7+4 sqrt 2
b. √ 7+4 sqrt 3
c. √ 7-4 sqrt 2
d.√ 7-4 sqrt 3

Answer 1

tan 15° = (1-cos30°)/sin30° = sin30°/(1+cos30°)
use either to get what you want