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`)`;

Note
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`
Note Link with `−lm`.

DESCRIPTION

The `hypot`() function returns 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.

CONFORMING TO

C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD.

COLOPHON

This page is part of release 3.52 of the Linux `man-pages` project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man−pages/.

 Copyright 1993 David Metcalfe (david(@)prism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date.  The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein.  The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END References consulted:     Linux libc source code     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)     386BSD man pages Modified 1993-07-24 by Rik Faith (faith(@)cs.unc.edu) Modified 2002-07-27 by Walter Harms (walter.harms(@)informatik.uni-oldenburg.de)