sqrt(1) square root function

Other Alias

sqrtf, sqrtl

## SYNOPSIS

#include <math.h>

double sqrt(double x);
float sqrtf(float
x);
long double sqrtl(long double
x);

## DESCRIPTION

These functions shall compute the square root of their argument x, sqrt(x).

An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

## RETURN VALUE

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

For finite values of x < -0, a domain error shall occur, and  either a NaN (if supported), or  an implementation-defined value shall be returned.

If x is NaN, a NaN shall be returned.

If x is ±0 or +Inf, x shall be returned.

If x is -Inf, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be returned.

## ERRORS

These functions shall fail if:

Domain Error
The finite value of x is < -0,  or x is -Inf.

If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno 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.

## Taking the Square Root of 9.0

```
#include <math.h>
...
double x = 9.0;
double result;
...
result = sqrt(x);

```

## APPLICATION USAGE

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.

None.

None.