# ATN Function

#### Purpose:

To return the arctangent of x, when x is expressed in radians.

#### Syntax:

    ATN(x)

#### Comments:

The result is within the range of -π/2 to π/2.

The expression x may be any numeric type. The evaluation of ATN is performed in single precision unless the /d switch is used when GW-BASIC is executed.

To convert from degrees to radians, multiply by π/180.

#### Examples:

    10 INPUT X
    20 PRINT ATN(X)
    RUN
     ? 3
     1.249046

Prints the arctangent of 3 radians (1.249046).