sin派/12-根号3 cos派/12的值

题目

sin派/12-根号3 cos派/12的值

答案

原式=1/2*(1/2*sinπ/12-√3/2*cosπ/12)
=2(sinπ/12cosπ/3-cosπ/12sinπ/3)
=2sin(π/12-π/3)
=2sin(-π/4)
=2*(-√2/2)
=-√2