302班

#include <stdio.h>

float sqrt(float x)
 {
   const float epsilon= 0.0001;
   float guess=1.0;
   if(x<0)
   {
    printf("Negative argument to squareRoot.\n");
    return -1.0;
   } 
   while (((guess*guess)-x)>=epsilon)
   {
    guess=(x/guess+guess)/2.0;
   }
   return guess;
 
 }
 void qiuJie(int a,int b,int c)
{
   float result=float(b*b-4*a*c);
   if(result<0)
   {
     printf("方程的根是复数!\n");
   }
   else
   {
     float x1=(-b+sqrt(result))/(2*a);
  printf("The first answer is %.2f.\n",x1);
  float x2=(-b-sqrt(result))/(2*a);
  printf("The second answer is %.2f.\n",x2);
   }
}
 

int main(void)
{
  int num1,num2,num3;
  printf("Enter three numbers !\n");
  scanf("%i",&num1);
  scanf("%i",&num2);
  scanf("%i",&num3);
  qiuJie(num1,num2,num3); 
  return 0;
}