double sqrt (double x);
      float sqrt (float x);
long double sqrt (long double x);
     double sqrt (T x);           // additional overloads for integral types

• القيمة المراد ايجاد جذرها x

    /* sqrt example */
    #include <stdio.h>     /* printf */
    #include <math.h>       /* sqrt */

    int main ()
    {
    double param, result;
    param = 1024.0;
    result = sqrt (param);
    printf ("sqrt(%f) = %f\n", param, result );
    return 0;
    }