{{keywords>wiki library source code example reference}}
===== sqrt =====
<code cpp>
    double sqrt(double);
</code>

returns the square root

===== cpp Sourcecode Example =====

<code cpp>
#include <iostream> /* including standard library */
#include <cmath> /* including math library */

using namespace std;
int main ( void )
{

  //cout.setf(ios::fixed, ios::floatfield);
  cout.precision(8);

  cout << "square root from 4.2 is " << sqrt (4.2) << endl;
  return 0;
}
</code>

==== output ====
  square root from 4.2 is 2.0493902