化简:cos83°+sin75°sin8°/cos7°-cos75°cos82°
问题描述：
化简:cos83°+sin75°sin8°/cos7°-cos75°cos82°
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.