atan
description
Syntax
DOUBLE atan(DOUBLE x)
返回x的反正切值，x为弧度值.
example
mysql> select atan(0);
+-----------+
| atan(0.0) |
+-----------+
| 0 |
+-----------+
mysql> select atan(2);
+--------------------+
| atan(2.0) |
+--------------------+
| 1.1071487177940904 |
+--------------------+keywords
ATAN