Mathematical Library Functions atan(3M)
NAME
atan, atanf, atanl - arc tangent function
SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include
double atan(double x); float atanf(float x);long double atanl(long double x);
DESCRIPTION
These functions compute the principal value of the arc tangent of x.RETURN VALUES
Upon successful completion, these functions return the arctangent of x in the range [-pi/2,pi/2] radians.
If x is NaN, NaN is returned.If x is +_0, x is returned.
If x is +_Inf, +_pi/2 is returned.
ERRORS
No errors are defined.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:SunOS 5.11 Last change: 12 Jul 2006 1
Mathematical Library Functions atan(3M)____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
| Standard | See standards(5). ||_____________________________|_____________________________|
SEE ALSO
atan2(3M), isnan(3M), math.h(3HEAD), tan(3M), attributes(5), standards(5)SunOS 5.11 Last change: 12 Jul 2006 2