标签：-- span blog logs bsp log color round mysql
ACOS(x) 用于返回 x 的反余弦，即余弦是 x 的值
mysql> SELECT ACOS(1), ACOS(0), ROUND(ACOS(0.5403023058681397)); +---------+--------------------+---------------------------------+ | ACOS(1) | ACOS(0) | ROUND(ACOS(0.5403023058681397)) | +---------+--------------------+---------------------------------+ | 0 | 1.5707963267948966 | 1 | +---------+--------------------+---------------------------------+
标签：-- span blog logs bsp log color round mysql
原文地址：http://www.cnblogs.com/pzk7788/p/6891909.html
