Question

2 cos 15°(sin 15° + cos 15°)-1=

Answer 1

Verified answer

2 cos 15 (sin 15 + cos 15) - 1 =
= (2 cos 15 sin 15) + (2cos² 15 - 1)
= sin 2(15) + cos 2(15)
= sin 30 + cos 30
= 1/2 + 1/2 √3
= 1/2 (1 + √3)