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(tan5°-cot5°)×
cos70°
1+sin70°
=______.
人气:374 ℃ 时间:2020-09-26 12:16:03
解答
(tan5°-cot5°)×cos70°1+sin70°=(sin5°cos5°-cos5°sin5°)•sin20°1+cos20°=sin25°−cos25°sin5°cos5°•sin20°1+cos20°=−cos10°12sin10°•2sin10°cos10°2cos210°=-2,故答案为:-2....
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