printf("please enter a:");
scanf("%f",a);
printf("please enter epsilon:");
scanf("%f",e);
if e<0 || a<0  {
 printf("epsilon and a need to be positive") ;
 return 0;
}
if e<10^(-6) {
 printf("epsilon too small (less than 10^-6)") ;
 return 0;
}
x1=1;
i=1;
x=x1;
while (abs(a-x^2)>=e)
{
 i++;
 x=0.5*(x+a/x);
}
printf("i=%d , xi=%f \n",i,x);
return 1;