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

NAME
     atan -- arc tangent function of one variable

SYNOPSIS
     #include <math.h>

     double
     atan(double x);

     long double
     atanl(long double x);

     float
     atanf(float x);

DESCRIPTION
     The atan() function computes the principal value of the arc tangent of x.
     The result is 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) The atan() function conforms to ISO/IEC 9899:1999(E).

BSD                            November 18, 2002                           BSD