In this example you will learn, how you can find the root of a quadratic equation in c.
b2-4ac is known as discriminant of quadratic equation. it tell the nature of root
if b2-4ac>0 roots are real and different
if b2-4ac<0 roots are complex and different
if b2-4ac=0 roots are real and equal
#include<stdio.h>
#include<math.h>
int main()
{
float det,a,b,c,root1,root2,real,imag;
printf("\n enter the value of coefficint a,b and c:");
scanf("%f %f %f",&a,&b,&c);
/* fid the discrimant value*/
det=(b*b)-(4*a*c);
if(det>0)
{
root1=(-b+sqrt(det))/(2*a);
root2=(-b-sqrt(det))/(2*a);
printf("\n root are real and different");
printf("\n root1=%f and root2=%f",root1,root2);
}
else if(det==0)
{
root1=root2=-b/(2*a);
printf("\n since d==0, root are real and equal");
printf("\n root1=root2=%f",root1);
}
else
{
real=(-b)/(2*a);
imag=sqrt(-det)/(2*a);
printf("\n determinant value is less than 0, hence root are complex and diffrent");
printf("\n root1=%f+%fi and root2=%f-%fi",real,imag,real,imag);
}
return 0;
}enter the value of coefficint a,b and c:5 9 2 root are real and different root1=-0.259688 and root2=-1.540312
