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sqrt(3p) — Linux manual page

PROLOG \|NAME \|SYNOPSIS \|DESCRIPTION \|RETURN VALUE \|ERRORS \|EXAMPLES \|APPLICATION USAGE \|RATIONALE \|FUTURE DIRECTIONS \|SEE ALSO \|COPYRIGHT

SQRT(3P)                POSIX Programmer's ManualSQRT(3P)

PROLOG top

       This manual page is part of the POSIX Programmer's Manual.  The       Linux implementation of this interface may differ (consult the       corresponding Linux manual page for details of Linux behavior), or       the interface may not be implemented on Linux.

NAME top

       sqrt, sqrtf, sqrtl — square root function

SYNOPSIS top

       #include <math.h>       double sqrt(doublex);       float sqrtf(floatx);       long double sqrtl(long doublex);

DESCRIPTION top

       The functionality described on this reference page is aligned with       the ISO C standard. Any conflict between the requirements       described here and the ISO C standard is unintentional. This       volume of POSIX.1‐2017 defers to the ISO C standard.       These functions shall compute the square root of their argumentx,√‾x.       An application wishing to check for error situations should seterrno to zero and callfeclearexcept(FE_ALL_EXCEPT) before calling       these functions. On return, iferrno is non-zero orfetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |       FE_UNDERFLOW) is non-zero, an error has occurred.

RETURN VALUE top

       Upon successful completion, these functions shall return the       square root ofx.       For finite values ofx < -0, a domain error shall occur, and       either a NaN (if supported), or an implementation-defined value       shall be returned.       Ifx is NaN, a NaN shall be returned.       Ifx is ±0 or +Inf,x shall be returned.       Ifx is -Inf, a domain error shall occur, and a NaN shall be       returned.

ERRORS top

       These functions shall fail if:       Domain Error                   The finite value ofx is < -0, orx is -Inf.                   If the integer expression (math_errhandling &                   MATH_ERRNO) is non-zero, thenerrno shall be set to[EDOM].  If the integer expression (math_errhandling &                   MATH_ERREXCEPT) is non-zero, then the invalid                   floating-point exception shall be raised.The following sections are informative.

EXAMPLES top

Taking the Square Root of 9.0           #include <math.h>           ...           double x = 9.0;           double result;           ...           result = sqrt(x);

APPLICATION USAGE top

       On error, the expressions (math_errhandling & MATH_ERRNO) and       (math_errhandling & MATH_ERREXCEPT) are independent of each other,       but at least one of them must be non-zero.

RATIONALE top

       None.

FUTURE DIRECTIONS top

       None.

COPYRIGHT top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 by the Institute of Electrical and Electronics Engineers,       Inc and The Open Group.  In the event of any discrepancy between       this version and the original IEEE and The Open Group Standard,       the original IEEE and The Open Group Standard is the referee       document. The original Standard can be obtained online athttp://www.opengroup.org/unix/online.html .       Any typographical or formatting errors that appear in this page       are most likely to have been introduced during the conversion of       the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017SQRT(3P)

Pages that refer to this page:math.h(0p), atan2(3p), hypot(3p)

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