求sin(派/12)-根号3cos(派/12)的值.
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![求sin(派/12)-根号3cos(派/12)的值.](/uploads/image/z/7018652-20-2.jpg?t=%E6%B1%82sin%28%E6%B4%BE%2F12%29-%E6%A0%B9%E5%8F%B73cos%28%E6%B4%BE%2F12%29%E7%9A%84%E5%80%BC.)
求sin(派/12)-根号3cos(派/12)的值.
求sin(派/12)-根号3cos(派/12)的值.
求sin(派/12)-根号3cos(派/12)的值.
原式=2倍[1/2倍sin(派/12)-根号3/2倍cos(派/12)]
=2倍[sin(派/12)乘cos(派/3)-cos(派/12)乘sin(派/3)]
=2倍sin(派/12-派/3)
=2倍sin(-派/4)
=-根号2
这道题考察的是两角和与差的三角函数的公式的逆运算.不过要先变形,在构造公式