## table of contents

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

# NAME¶

hypot, hypotf, hypotl - Euclidean distance function

# SYNOPSIS¶

#include <math.h>

double hypot(doublex, doubley);float hypotf(floatx, floaty);long double hypotl(long doublex, long doubley);

Link with *-lm*.

**hypot**():

|| _XOPEN_SOURCE

|| /* Since glibc 2.19: */ _DEFAULT_SOURCE

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

**hypotf**(),

**hypotl**():

|| /* 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 the hypotenuse 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 5.10 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/.

2017-09-15 |