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].

# SEE ALSO

acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3)

# STANDARDS

The atan() functions conforms to ISO/IEC 9899:1999 (“ISO C99”).

January 29, 2013 | NetBSD 8.2