ATAN(3) Library Functions Manual ATAN(3)
NAME
atan, atanfarc tangent function of one variable
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
atan(double x);
float
atanf(float x);
DESCRIPTION
The atan() and atanf() functions compute the principal value of the arc tangent of x in the range [-π/2, +π/2].
SEE ALSO
STANDARDS
The atan() functions conforms to ANSI X3.159-1989 (“ANSI C”).