(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=

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(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=(sinπ/12+cosπ/12)(sinπ/12-cosπ

(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=
(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=

(sinπ/12+cosπ/12)(sinπ/12-cosπ/12)=
原式=sin²(π/12)-cos²(π/12)
=-cos(2×π/12)
=-cos(π/6)
=-√3/2

(sin5π/12-sinπ/12)(cos5π/12+cosπ/12)
=(cosπ/12 - sinπ/12)(sinπ/12 + cosπ/12)
=cos²(π/12) - sin²(π/12)
=cos(π/6)
=(根号3)/2
以上回答你满意么?