## Linux and UNIX Man Pages

Test Your Knowledge in Computers #247
Difficulty: Easy
By 1973, the File Transfer Protocol (FTP) specification had been defined (RFC 354) and implemented, enabling file transfers over the ARPANET.
True or False?

# hypot(3m) [opensolaris man page]

```hypot(3M)						  Mathematical Library Functions						 hypot(3M)

NAME
hypot, hypotf, hypotl - Euclidean distance function

SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>

double hypot(double x, double y);

float hypotf(float x, float y);

long double hypotl(long double x, long double y);

DESCRIPTION
These functions compute the length of the square root of x^2 + y^2 without undue overflow or underflow.

RETURN VALUES
Upon  successful  completion,  these  functions return the length of the hypotenuse of a right angled triangle with sides of length x^2 and
y^2.

If the correct value would cause overflow, a range error occurs and hypot(), hypotf(), and hypotl() return the value of the macro HUGE_VAL,
HUGE_VALF, and HUGE_VALL, respectively.

If x or y is +-Inf, +Inf is returned even if one of x or y is NaN.

If x or y is NaN and the other is not +-Inf, a NaN is returned.

ERRORS
These functions will fail if:

Range Error    The result overflows.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the overflow floating-point exception is raised.

USAGE
hypot(x,y), hypot(y,x), and hypot(x, -y) are equivalent.

hypot(x, +-0) is equivalent to fabs(x).

These functions takes precautions against underflow and overflow during intermediate steps of the computation.

An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
either examine the return value or check the floating point exception flags to detect exceptions.

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:

+-----------------------------+-----------------------------+
|      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
+-----------------------------+-----------------------------+
|Interface Stability	     |Standard			   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+