ATAN(3) BSD Library Functions Manual ATAN(3)NAME
atan, atanf, atanl — arc tangent functions 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.
RETURN VALUES
These functions return the arc tangent in the range [-π/2, +π/2] radians.
SEE ALSOacos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3),
tan(3), tanh(3)STANDARDS
The atan(), atanf(), and atanl() functions conform to ISO/IEC 9899:1999
(“ISO C99”).
BSD July 31, 2008 BSD