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”).