求cos15°-tan15°/cos15°+sin15°

题目

求cos15°-tan15°/cos15°+sin15°

答案

是 (cos 15°-tan 15°) / (cos 15°+sin 15°) 吗?= = = = = = = = =因为 sin 15°=sin (45°-30°) =sin 45°cos 30°-cos 45°sin 30° =(根号2) /2 *(根号3) /2 -(...