302班

#include <stdio.h>
 float absoluteValue(float x)
 {
   if(x<0)
   {
    x=-x;
   }
   return x;
 }
 float squareRoot(float x)
 {
   const float epsilon= 0.0001;
   float guess=1.0;
   if(x<0)
   {
    printf("Negative argument to squareRoot.\n");
    return -1.0;
   } 
   while (absoluteValue((guess*guess)-x)>=epsilon)
   {
    guess=(x/guess+guess)/2.0;
   }
   return guess;
 
 }
int main(void)
{
  float  number; 
  printf("Enter an float number!\n");
  scanf("%f",&number);
 
  printf("The squareRoot of number %f is %f.\n",number,squareRoot(number));
  return 0;
}