Question

2.cosπ/12 +√3sinπ/12的值为(） A-2 B√2 C1/2 D√3？

Answer 1

cosπ/12 +√3sinπ/12 = 2[(1/2)cos(π/12) + (√3/2)sin(π/12)]
= 2[sin(π/6)cos(π/12) + cos(π/6)sin(π/12)]
= 2sin(π/6+π/12) = 2sin(π/4) = √2, B.