化简:(cos15度sin9度+sin6度)/(sin15度sin9度-cos6度)原式=[cos15sin9+sin(15-9)]/[sin15sin9-cos(15-9)]=(cos15sin9+sin15cos9-cos15sin9)/(sin15sin9-cos15cos9-sin15sin9)=sin15cos9/(-cos15cos9)=sin15/cos15=-tan15=-tan(45-30)=-(tan45-tan30
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/14 16:30:39
![化简:(cos15度sin9度+sin6度)/(sin15度sin9度-cos6度)原式=[cos15sin9+sin(15-9)]/[sin15sin9-cos(15-9)]=(cos15sin9+sin15cos9-cos15sin9)/(sin15sin9-cos15cos9-sin15sin9)=sin15cos9/(-cos15cos9)=sin15/cos15=-tan15=-tan(45-30)=-(tan45-tan30](/uploads/image/z/3137663-47-3.jpg?t=%E5%8C%96%E7%AE%80%EF%BC%9A%EF%BC%88cos15%E5%BA%A6sin9%E5%BA%A6%2Bsin6%E5%BA%A6%EF%BC%89%2F%EF%BC%88sin15%E5%BA%A6sin9%E5%BA%A6-cos6%E5%BA%A6%EF%BC%89%E5%8E%9F%E5%BC%8F%3D%5Bcos15sin9%2Bsin%2815-9%29%5D%2F%5Bsin15sin9-cos%2815-9%29%5D%3D%28cos15sin9%2Bsin15cos9-cos15sin9%29%2F%28sin15sin9-cos15cos9-sin15sin9%29%3Dsin15cos9%2F%28-cos15cos9%29%3Dsin15%2Fcos15%3D-tan15%3D-tan%2845-30%29%3D-%28tan45-tan30)
化简:(cos15度sin9度+sin6度)/(sin15度sin9度-cos6度)原式=[cos15sin9+sin(15-9)]/[sin15sin9-cos(15-9)]=(cos15sin9+sin15cos9-cos15sin9)/(sin15sin9-cos15cos9-sin15sin9)=sin15cos9/(-cos15cos9)=sin15/cos15=-tan15=-tan(45-30)=-(tan45-tan30
化简:(cos15度sin9度+sin6度)/(sin15度sin9度-cos6度)
原式=[cos15sin9+sin(15-9)]/[sin15sin9-cos(15-9)]
=(cos15sin9+sin15cos9-cos15sin9)/(sin15sin9-cos15cos9-sin15sin9)
=sin15cos9/(-cos15cos9)
=sin15/cos15
=-tan15
=-tan(45-30)
=-(tan45-tan30)/(1+tan45tan30)
=-2+√3
中的
=sin15cos9/(-cos15cos9)这一步到
=sin15/cos15
是怎么得到的?用的什么公式?
化简:(cos15度sin9度+sin6度)/(sin15度sin9度-cos6度)原式=[cos15sin9+sin(15-9)]/[sin15sin9-cos(15-9)]=(cos15sin9+sin15cos9-cos15sin9)/(sin15sin9-cos15cos9-sin15sin9)=sin15cos9/(-cos15cos9)=sin15/cos15=-tan15=-tan(45-30)=-(tan45-tan30
=sin15cos9/(-cos15cos9)这一步到(分子、分母都除以cos9 得到的)
应该是=-sin15/cos15