แบบฝึกหัดที่ 7

จงสร้างโปรแกรมหาค่า root จากสมการ ax^2 + bx + c = 0

#include
#include
int main (void)
{
float a,b,c;
double x1,x2,sum,d;
printf("input a:\t");
scanf("%f",&a);
printf("input b:\t");
scanf("%f",&b);
printf("input c:\t");
scanf("%f",&c);
d = (b*b)-(4*a*c);
sum = sqrt(d);
x1 = (-b+sum)/(2*a);
x2 = (-b-sum)/(2*a);
if(a==0 && b==0)
{
printf("Invalid coefficient");
}
else if (a==0 && b!=0)
{
printf("Only one root is = %lf",x1);
}
else if(d<0)
{
printf("Root is Imaginary");
}
else if(d>0)
{
printf("Result Roots are x1= %lf and x2= %lf",x1,x2);
}
else
{
printf("Error");
}
return 0;
}