NAME

       hypot, hypotf, hypotl - Euclidean distance function

LIBRARY

       Math library (libm, -lm)

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():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || _XOPEN_SOURCE
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

       hypotf(), hypotl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 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 │
       └──────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       C11, POSIX.1-2008.

HISTORY

       C99, POSIX.1-2001.

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

SEE ALSO

       cabs(3), sqrt(3)