ATAN(3) 	       FreeBSD Library Functions Manual 	       ATAN(3)

NAME
     atan, atanf -- arc tangent functions of one variable

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     double
     atan(double x);

     float
     atanf(float x);

DESCRIPTION
     The atan() and the atanf() functions compute the principal value of the
     arc tangent of x.	For a discussion of error due to roundoff, see
     math(3).

RETURN VALUES
     The atan() and the atanf() function returns the arc tangent in the range
     [-pi/2, +pi/2] radians.

SEE ALSO
     acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3),
     tan(3), tanh(3)

STANDARDS
     The atan() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

FreeBSD 7.2			  May 2, 1991			   FreeBSD 7.2

NAME - LIBRARY - SYNOPSIS - DESCRIPTION - RETURN VALUES - SEE ALSO - 
STANDARDS -