opendarwin man page for atan

ATAN(3) 						   BSD Library Functions Manual 						   ATAN(3)

NAME
     atan -- arc tangent function of one variable

SYNOPSIS
     #include <math.h>

     double
     atan(double x);

DESCRIPTION
     The atan() function computes the principal value of the arc tangent of x in the range [-pi/2, +pi/2].

SPECIAL VALUES
     atan(+-0) returns +-0.

     atan(+-infinity) returns +-pi/2

SEE ALSO
     acos(3), asin(3), atan2(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3), math(3), matherr(3) The atan() function conforms to ISO/IEC
     9899:1999(E).

BSD
								 November 18, 2002							       BSD