原式=sin(π/4-π/6)sin(π/4+sinπ/6)=(sinπ/4cosπ/6-cosπ/4sinπ/6)(sinπ/4cosπ/6+cosπ/4sinπ/6)=(sinπ/4cosπ/6)²-(cosπ/4sinπ/6)²=(√6/4)²-(√2/4)²=6/16-2/16=1/4