求值:cos255°+sin(-7π/3)+cos(-2040°)+sin(-16π/3)

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求值:cos255°+sin(-7π/3)+cos(-2040°)+sin(-16π/3)
求值:cos255°+sin(-7π/3)+cos(-2040°)+sin(-16π/3)

求值:cos255°+sin(-7π/3)+cos(-2040°)+sin(-16π/3)
cos255°+sin(-7π/3)+cos(-2040°)+sin(-16π/3)=-cos45-sin(π/3)+cos120+sin(2π/3)=-根号(2)/2-根号(3)/2-1/2+根号(3)/2=-(根号(2)+1)/2