化简：sin40度（tan10度-根号3)

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原辩颂李式=sin40°(tan10°-tan60°)
=sin40°(sin(10°-60°)/(cos10°cos60°))
=2sin40°sin(-50°)/cos10°
=-2sin40°cos40°/携迟樱埋sin80°
=-sin80°/sin80°
=-1

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