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化简:cos83°+sin75°sin8°/cos7°-cos75°cos82°
人气:205 ℃ 时间:2020-04-04 22:23:42
解答
=[sin(15-8)+cos15sin8]/[cos(15-8)-sin15sin8] =[(sin15cos8-cos15sin8)+cos15sin8]/[(cos15cos8+sin15sin8)-sin15sin8] =sin15cos8/(cos15cos8) =tan15 =(1-cos30)/sin30 =(1-√3/2)/(1/2) =2-√3.
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