You are here

c program to find roots of quadratic equation

c program to find roots of quadratic equation: This program calculates roots of a quadratic equation. Coefficients are assumed to be integers but roots may be real.. Discriminant (b*b-4*a*c) decides the nature of roots. In the program j stands for iota.

C programming code

#include <stdio.h>
#include <math.h>
int main()
   int a, b, c, d;
   double root1, root2;
   printf("Enter a, b and c where a*x*x + b*x + c = 0\n");
   scanf("%d%d%d", &a, &b, &c);
   d = b*b - 4*a*c;
   if (d < 0) { //complex roots
     printf("First root = %.2lf + j%.2lf\n", -b/(double)(2*a), sqrt(-d)/(2*a));
     printf("Second root = %.2lf - j%.2lf\n", -b/(double)(2*a), sqrt(-d)/(2*a));
   else { //real roots
      root1 = (-b + sqrt(d))/(2*a);
      root2 = (-b - sqrt(d))/(2*a);
      printf("First root = %.2lf\n", root1);
      printf("Second root = %.2lf\n", root2);
   return 0;
Compiler used: 
Output of program: 
Quadratic quation program output