来自侯治宇的问题
(tan5°-cot5°)×cos70°1+sin70°=______.
(tan5°-cot5°)×cos70°1+sin70°=______.
1回答
2020-04-11 09:59
(tan5°-cot5°)×cos70°1+sin70°=______.
(tan5°-cot5°)×cos70°1+sin70°=______.
(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....