(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=
问题描述:
(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=
答
原式=sin²(π/12)-cos²(π/12)
=-cos(2×π/12)
=-cos(π/6)
=-√3/2