求sin π/12-(根号3)cos π/12

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求sin π/12-(根号3)cos π/12

求sin π/12-(根号3)cos π/12
求sin π/12-(根号3)cos π/12

求sin π/12-(根号3)cos π/12
用辅助角公式
原式=2(1/2sinπ/12-(根号3)/2cosπ/12)
=2(cosπ/3sinπ/12-sinπ/3cosπ/12)
=2[sin(π/12-π/3)]
=-2(sinπ/4)
=-2*(根号2)/2
=-根号2

原式=2(1/2sin兀/12-(根号3)/2cos兀/12)
=2(cos兀/3sin兀/12-sin兀/3cos兀/12)
=2[cos(兀/3-兀/12)]
=-2(cos兀/4)
=-2*(根号2)/2
=-根号2

负根号二