# hypot

```HYPOT(3)                   Linux Programmer's Manual                  HYPOT(3)

NAME
hypot, hypotf, hypotl - Euclidean distance function

SYNOPSIS
#include <math.h>

double hypot(double x, double y);
float hypotf(float x, float y);
long double hypotl(long double x, long double y);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

hypot():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
hypotf(), hypotl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99

DESCRIPTION
These  functions  return  sqrt(x*x+y*y).   This  is  the  length of the
hypotenuse of a right-angled triangle with sides of length x and y,  or
the distance of the point (x,y) from the origin.

The calculation is performed without undue overflow or underflow during
the intermediate steps of the calculation.

RETURN VALUE
On success, these functions return the length of a right-angled  trian-
gle with sides of length x and y.

If x or y is an infinity, positive infinity is returned.

If x or y is a NaN, and the other argument is not an infinity, a NaN is
returned.

If the result overflows, a range error occurs, and the functions return
HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively.

If  both  arguments are subnormal, and the result is subnormal, a range
error occurs, and the correct result is returned.

ERRORS
See math_error(7) for information on how to determine whether an  error
has occurred when calling these functions.

The following errors can occur:

Range error: result overflow
errno  is  set  to ERANGE.  An overflow floating-point exception
(FE_OVERFLOW) is raised.

Range error: result underflow
An underflow floating-point exception (FE_UNDERFLOW) is raised.

These functions do not set errno for this case.

ATTRIBUTES
For  an  explanation  of  the  terms  used   in   this   section,   see
attributes(7).

+----------------------------+---------------+---------+
|Interface                   | Attribute     | Value   |
+----------------------------+---------------+---------+
|hypot(), hypotf(), hypotl() | Thread safety | MT-Safe |
+----------------------------+---------------+---------+

CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.

The variant returning double also conforms to SVr4, 4.3BSD.