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

# NAME¶

hypot, hypotf, hypotl - Euclidean distance function# SYNOPSIS¶

Link with#include <math.h>double hypot(doublex, doubley);float hypotf(floatx, floaty);long double hypotl(long doublex, long doubley);

*-lm*.

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¶

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.

# SEE ALSO¶

cabs(3), sqrt(3)# COLOPHON¶

This page is part of release 3.74 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 http://www.kernel.org/doc/man-pages/.

2010-09-20 |