早教吧 育儿知识 作业答案 考试题库 百科 知识分享

tan12分之π-(tan12分之π)分之1,tan12分之π-(tan12分之π)分之1,

题目详情
tan12分之π-(tan12分之π)分之1,
tan12分之π-(tan12分之π)分之1,
▼优质解答
答案和解析
tan12分之π-(tan12分之π)分之1

= sin(π/12)/cos(π/12)-cos(π/12)/sin(π/12)
=[sin^2(π/12)-cos^2(π/12)]/[cos(π/12)sin(π/12)]
=-cos(2π/12)/[1/2sin(2π/12)]
=(-√3/2)/(1/4)
=-2√3