Calculation of Roots of Quadratic Equation

CODING:
#include <stdio.h> 
#include <math.h> 
int main()
{
float a, b, c, determinant, r1,r2, real, imag; 
printf("Enter coefficients a, b and c: ");
scanf("%f%f%f",&a,&b,&c); 
determinant=b*b-4*a*c; 
if (determinant>0) 
{ 

r1= (-b+sqrt(determinant))/(2*a);

r2= (-b-sqrt(determinant))/(2*a);

printf("Roots are: %.2f and %.2f",r1 , r2);
}

else if (determinant==0) 
{

r1 = r2 = -b/(2*a); 

printf("Roots are: %.2f and %.2f", r1, r2);

} 
else
 { 

real= -b/(2*a);

imag = sqrt(-determinant)/(2*a);

printf("Roots are: %.2f+%.2fi and %.2f-%.2fi", real, imag, real, imag); 

} 

return 0;

}