ATAN(3) |
Library Functions Manual |
ATAN(3) |
NAME
atan, atanf, atanl — arc tangent function of one variable
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
atan(double x);
float
atanf(float x);
long double
atanl(long double x);
DESCRIPTION
The atan(), atanf(), and atanl() functions compute the principal value of the arc tangent of x in the range [-pi/2, +pi/2].
STANDARDS
The atan() functions conforms to ISO/IEC 9899:1999 (“ISO C99”).