雷山县望丰乡三角田村:sin50°(1+tan10°)=?要过程

来源:百度文库 编辑:中科新闻网 时间:2024/05/07 04:39:04
没人懂吗??55555`````

sin50(1+√3tan10)
=sin50[1+(√3sin10/cos10)]
=sin50[cos10+√3sin10)/cos10]
=2sin50[(1/2)cos10+(√3/2)sin10)/cos10]
=2sin50[cos60cos10+sin60sin10)/cos10]
=2sin50cos(60-10)/cos10
=2sin50cos50/cos10
=sin100/cos10
=cos10/cos10
=1

少了个√3吧 题目错了