> 数学 >
计算:sin(π/12)sin(5π/12)
要用二倍角与半角的公式
人气:471 ℃ 时间:2020-06-06 02:11:39
解答
sin(π/12)sin(5π/12)
=-1/2[cos(π/12+5π/12)-cos(π/12-5π/12)]
=-1/2(cosπ/2-cosπ/3)
=-1/2(0-1/2)
=1/4
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版