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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);

       Link with -lm.

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

       hypot(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE ||
       _ISOC99_SOURCE; or cc -std=c99
       hypotf(), hypotl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
       || _ISOC99_SOURCE; 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 3.24 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/.

                                  2008-08-05