sin(pi/12)=?
问题描述：
sin(pi/12)=?
答
sin(pi/12)=sin (pi/3-pi/4)=sin pi/3cospi/4-cospi/3sinpi/4=根号6/4-根号2/4
答
cos(π/6)=1-2[sin(π/12)]^2
所以sin(π/12)=√[(1-cos(π/6)/2]=√[(3-√3)/6]