C program for solving quadratic equation

C program : How to solve quadratic equation using C

#include<stdio.h>

#include<math.h>

int main(){

float a,b,c;

float d,root1,root2;

printf("Enter a, b and c of quadratic equation: ");

scanf("%f%f%f",&a,&b,&c);

d = b * b - 4 * a * c;

if(d < 0){

printf("Roots are complex number.\n");

printf("Roots of quadratic equation are: ");

printf("%.3f%+.3fi",-b/(2*a),sqrt(-d)/(2*a));

printf(", %.3f%+.3fi",-b/(2*a),-sqrt(-d)/(2*a));

return 0;

}

elseif(d==0){

printf("Both roots are equal.\n");

root1 = -b /(2* a);

printf("Root of quadratic equation is: %.3f ",root1);

return 0;

}

else{

printf("Roots are real numbers.\n");

root1 = ( -b + sqrt(d)) / (2* a);

root2 = ( -b - sqrt(d)) / (2* a);

printf("Roots of quadratic equation are: %.3f , %.3f",root1,root2);

}

return 0;

}