# hypot man page

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***);**

`Link with `

*-lm*.

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

_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

|| _XOPEN_SOURCE

|| /* Since glibc 2.19: */ _DEFAULT_SOURCE

|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

**hypotf**(), **hypotl**():

_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

|| /* Since glibc 2.19: */ _DEFAULT_SOURCE

|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

## 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 triangle 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.

## See Also

## Colophon

This page is part of release 4.09 of the Linux *man-pages* project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

## Referenced By

hypotf(3) and hypotl(3) are aliases of hypot(3).