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# sqrt

Square root function
View other versions (4)

## Interface

#include <math.h>double sqrt (double x)long sqrtl (long double x)float sqrtf (float x)#include <complex.h>complex sqrt (complex x)double complex csqrt (double complex x)float complex csqrtf (float complex x)long double complex csqrtl (long double complex x)

## Description

The sqrt function computes the non-negative square root of x, i.e

sqrt(x)$\inline&space;=\sqrt&space;x$

For complex numbers x, sqrt returns the complex root of x, using the following formula
$\sqrt{x}&space;=&space;\sqrt&space;{&space;\mathrm{abs}(x)}&space;\left[&space;\cos\left(\frac{\mathrm{arg}(x)}{2}\right)&space;+&space;i&space;\sin\left(\frac{\mathrm{arg}(x)}{2}\right)&space;\right]$
where $\inline&space;\mathrm{arg}(x)$ is the argument of x.

Example:
##### Example - Square root function
Workings
#include <stdio.h>
#include <math.h>
int main()
{
double x = 1234321;
double result = sqrt(x);
printf("The square root of %.2lf is %.2lf\n", x, result);
return 0;
}
Solution
Ouput:
The square root of 1234321.00 is 1111.00

## Special Values

sqrt ( -0 ) returns -0.

sqrt ( x ) returns a NaN and generates a domain error for x < 0.

## Standards

The sqrt function conforms to ISO/IEC 9899:1999(E).

## Compatibility

DOSUNIXWindowsANSI CC++ only
sqrtlâ€¢â€¢
Real sqrtâ€¢â€¢â€¢â€¢
Complex sqrtâ€¢â€¢â€¢
Complex csqrtâ€¢â€¢