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.

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