C语言程序与设计第四章

##例4.1

# include <stdio.h>
# include <math.h>
int main()
{
   
   
double a,b,c,disc,x1,x2,p,q;
scanf("%if%if%if",&a,&b,&c);
disc=b*b-4*a*c;
if(disc<0)
printf("This equation hasn't real roots\n");
else
{
   
   
p=-b/(2.0*a);
q=sqrt(disc)/(2.0*a);
x1=p+q;
x2=p-q;
printf("real roots:\nx1=%7.2f\nx2=%7.2f\n:,x1,x2);
}
return 0;
}

##例4.2 输入两个实数，按由小到大的顺序输出。

# include<stdio.h>
int main()
{
   
   
float a,b,t;
scanf("%f,%f",&a,&b)