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 [-pi/2, +pi/2] radians.
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(), atanf(), and atanl() functions conform to ISO/IEC 9899:1999 (``ISO C99'').
BSD
July 31, 2008 BSD