Purpose
ATAN() returns the arc tangent of a number. The arc tangent is an angle whose tangent is a number. The returned angle is given in radians, in the range of (-π/2, π/2).
Syntax
ATAN(number)
Parameters
number is of a numeric data type or any data type that can be implicitly converted to a numeric data type.
Return type
The return type is NUMBER.
Examples
Return the arc tangent of 0.5.
obclient> SELECT ATAN(0.5) FROM DUAL;
+-------------------------------------------+
| ATAN(0.5) |
+-------------------------------------------+
| .4636476090008061162142562314612144020285 |
+-------------------------------------------+
1 row in set