CODE

#include<stdio.h>
#include<math.h>
int main(){
    float a,b,c,discr,r1,r2,sqdis;
    printf("Enter the Coefficient of x(square) : ");
    scanf("%f",&a);
    printf("Enter the Coefficient of x : ");
    scanf("%f",&b);
    printf("Enter the Contant Term : ");
    scanf("%f",&c);
    discr =(b*b)- (4*a*c);
    if(a==0){
        printf("Since Coefficient of x(square) is zero hence it is not a QUADRATIC EQUATION\n");
    }
    else{
        if(discr<0){
        sqdis= sqrt(-discr);
        r1=(-b)/(2*a);
        r2= (sqdis)/(2*a);
        printf("Eqn %fx(square) + %f x + %f has complex roots = %f + i (%f), %f - i (%f)\n",a,b,c,r1,r2,r1,r2); 
        }
        else if(discr==0){
            r1=(-b)/(2*a);
            printf("Eqn %fx(square) + %f x + %f has one real root = %f\n",a,b,c,r1);  
        }
        else{
            sqdis= sqrt(discr);
            r1= ((-b)+ sqdis)/(2*a);
            r2= ((-b)- sqdis)/(2*a);
            printf("Eqn %fx(square) + %f x + %f has two distinct real roots = %f , %f \n",a,b,c,r1,r2); 

        }
    }
    return 0;
} 

We first of all calculate discriminant so that we can conclude whether roots are equal, distinct or imaginary.

discr =(b*b)- (4*a*c);

Now if roots are imaginary i.e. discr < 0, first we calculate square root of modulus of discriminant then we calculate real and imaginary parts of roots in r1 and r2 respectively.

sqdis= sqrt(-discr);
r1=(-b)/(2*a);
r2= (sqdis)/(2*a);

Roots will be r1 + r2 i and r1 – r2 i .

Now if roots are Equal i.e. discr = 0 then Roots are calculated and stored in r1.

r1=(-b)/(2*a);

Now if roots are real and distinct,first we calculate square root of modulus of discriminant then we calculate and store both roots in r1 and r2 respectively.

sqdis= sqrt(discr);
r1= ((-b)+ sqdis)/(2*a);
r2= ((-b)- sqdis)/(2*a);

OUTPUT