sqrt, sqrtl

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Header File

math.h

Category

Math Routines

Prototype

double sqrt(double x);

long double sqrtl(long double x);

Description

Calculates the positive square root.

sqrt calculates the positive square root of the argument x.

sqrtl is the long double version; it takes a long double argument and returns a long double result. Error handling for these functions can be modified through the functions _matherr and _matherrl.

Return Value

On success, sqrt and sqrtl return the value calculated, the square root of x. If x is real and positive, the result is positive. If x is real and negative, the global variable errno is set to

EDOM	Domain error

Example

#include <math.h>
#include <stdio.h>
int main(void)
{
   double x = 4.0, result;
   result = sqrt(x);
   printf("The square root of %lf is %lf\n", x, result);
   return 0;
}

Portability

	POSIX	Win32	ANSI C	ANSI C++
sqrt	+	+	+	+
sqrtl		+	+	+