[user02@FC4 Lesson12]$ cat -n sqrt.c

   1  #include <stdio.h>
   2  #include <math.h>        // Contains sqrt prototype
   3
   4  int main(void)
   5  {
   6     printf("The square root of 100.0 is %f\n", sqrt(100.0));

   7     printf("The square root of 10.0 is %f\n", sqrt(10.0));
   8     printf("The square root of 5. 0 is %f\n", sqrt(5.0));
   9
  10     return 0;
  11  }

[user02@FC4 Lesson12]$ gcc -o sqrt sqrt.c
[user02@FC4 Lesson12]$ ./sqrt
The square root of 100.0 is 10.000000
The square root of 10.0 is 3.162278
The square root of 5. 0 is 2.236068
[user02@FC4 Lesson12]$