Calculates the square root.
double sqrt(
double x
);
float sqrt(
float x
); // C++ only
long double sqrt(
long double x
); // C++ only
float sqrtf(
float x
);
Parameters
- x
Nonnegative floating-point value
Remarks
C++ allows overloading, so users can call overloads of sqrt that take float or long double types. In a C program, sqrt always takes and returns double.
Return Value
The sqrt function returns the square-root of x. If x is negative, sqrt returns an indefinite, by default.
Input |
SEH Exception |
Matherr Exception |
|---|---|---|
± QNAN,IND |
none |
_DOMAIN |
- ∞ |
INVALID |
_DOMAIN |
x>0 |
INVALID |
_DOMAIN |
Requirements
Routine |
Required header |
|---|---|
sqrt, sqrtf |
<math.h> |
For additional compatibility information, see Compatibility in the Introduction.
Example
// crt_sqrt.c
// This program calculates a square root.
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
int main( void )
{
double question = 45.35, answer;
answer = sqrt( question );
if( question < 0 )
printf( "Error: sqrt returns %.2f\n, answer" );
else
printf( "The square root of %.2f is %.2f\n", question, answer );
}
The square root of 45.35 is 6.73