SQRT(3M) | Mathematical Library Functions | SQRT(3M) |

sqrt, sqrtf, sqrtl - square root function

c99 [flag... ]file...-lm[library... ] #include <math.h>doublesqrt(doublex);

floatsqrtf(floatx);

long doublesqrtl(long doublex);

These functions compute the square root of their argument
*x*.

Upon successful completion, these functions return the square root
of *x*.

For finite values of *x* < −0, a domain error
occurs and either a NaN (if supported) or an implementation-defined value is
returned.

If *x* is NaN, a NaN is returned.

If *x* is ±0 or +Inf, *x* is returned.

If *x* is −Inf, a domain error occurs and a NaN is
returned.

These functions will fail if:

**Domain Error**

The finite value of *x* is < −0 or
*x* is −Inf.

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

The **sqrt()** function sets **errno** to **EDOM** if the
value of *x* is negative.

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.

An application can also set **errno** to 0 before calling
**sqrt()**. On return, if **errno** is non-zero, an error has
occurred. The **sqrtf()** and **sqrtl()** functions do not set
**errno**.

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE | ATTRIBUTE VALUE |

Interface Stability | Standard |

MT-Level | MT-Safe |

math.h(3HEAD), feclearexcept(3M), fetestexcept(3M), isnan(3M), attributes(7), standards(7)

July 12, 2006 | SunOS 5.11 |