求sin²20+cos²80+根号三sin²20cos80的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/18 02:50:57
![求sin²20+cos²80+根号三sin²20cos80的值](/uploads/image/z/2505474-18-4.jpg?t=%E6%B1%82sin%26%23178%3B20%2Bcos%26%23178%3B80%2B%E6%A0%B9%E5%8F%B7%E4%B8%89sin%26%23178%3B20cos80%E7%9A%84%E5%80%BC)
x){83OM@;9¶0~`Ovt") [%l((ed Dc1XVP3170)74s@4
tPPP 0257h7) +D@R*cA*bp6yv
求sin²20+cos²80+根号三sin²20cos80的值
求sin²20+cos²80+根号三sin²20cos80的值
求sin²20+cos²80+根号三sin²20cos80的值
sin20²+cos²80+√3sin20cos80
=(1-cos40)/2+(1+cos160)/2+√3/2(sin100-sin60)
=1-1/2cos40-1/2cos20-3/4+√3/2sin100
=1/4-1/2(cos40+cos20+√3/2sin80
=1/4-cos10cos30+√3/2sin80
=1/4-√3/2cos10+√3/2sin80
=1/4-√3/2cos10+√3/2cos10
=1/4