用诱导公式求这个简单的三角函数值.(急!)sin(-26π/3)
问题描述:
用诱导公式求这个简单的三角函数值.(急!)
sin(-26π/3)
答
sin(-26π/3)
=sin(-26π/3+5*2π)
=sin(4π/3)
=sin(π+π/3)
=-sinπ/3
=-√3/2