> 数学 >
若2sin(α/2+π/6)=1/2,求sin(6/π-α)的值
人气:345 ℃ 时间:2020-06-30 23:12:28
解答
∵2sin(α/2+π/6)=1/2
∴sin(α/2+π/6)=1/4

∴cos(π/3+α)
=cos[2(α/2+π/6)]
=1-sin²(α/2+π/6)
=1-2*1/16=7/8

∴sin(6/π-α)
=sin[π/2-(π/3+α)]
=cos(π/3+α)
=7/8
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版