化简 (1) (tan10°-根号3)*sin80 - 知识问答

化简 (1) (tan10°-根号3)*sin80°/cos40°（2）（根号3-tan18°）/（1+根号3 tan1

1个回答

(1)原式=（sin10/cos10-√3）*sin80/cos40
=(cos80/sin80-√3)*sin80/cos40
=(cos80-√3sin 80)/cos40
=-2sin(80-30)/cos40
=-2sin50/cos40
=-2cos40/cos40
=-2
(2)原式=(tan60-tan18)/(1+tan60tan18)
=tan(60-18)
=tan42

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