ATAN(3) BSD Library Functions Manual ATAN(3)NAMEatan — 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 [-π/2, +π/2].
SPECIAL VALUES
atan(�0) returns �0.
atan(�infinity) returns �pi/2
SEE ALSOacos(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