ATAN(3)

NAME
1.7 `atan', `atanf'--arc tangent

SYNOPSIS
     #include <math.h>
     double atan(double X);
     float atanf(float X);

DESCRIPTION
`atan' computes the inverse tangent (arc tangent) of the input value.
   `atanf' is identical to `atan', save that it operates on `floats'.

RETURNS
`atan' returns a value in radians, in the range of -pi/2 to pi/2.

PORTABILITY
`atan' is ANSI C. `atanf' is an extension.

SEE ALSO
atan is part of the library. The full documentation for is maintained as a Texinfo manual. If info and are properly installed at your site, the command

    info

will give you access to the complete manual.