PHP开发教程

MySQL acos()函数

ACOS(X)

这个函数返回X的反余弦。X值的范围必须在-1和1之间,否则返回 NULL。请看下面的例子:

mysql> SELECT ACOS(1);
+---------------------------------------------------------+
| ACOS(1)                                                 |
+---------------------------------------------------------+
| 0.000000                                                |
+---------------------------------------------------------+
1 row in set (0.00 sec)


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