Finding roots of a Quadratic equation using C

#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);
 }
 }