C Programming Code Examples

C > Mathematics Code Examples

The standard form of a quadratic equation is:



The standard form of a quadratic equation is:

ax*x + bx + c = 0, where
a, b and c are real numbers and
a ? 0

The term b*b-4ac is known as the determinant of a quadratic equation. The determinant tells the nature of the roots.

    If determinant is greater than 0, the roots are real and different.
    If determinant is equal to 0, the roots are real and equal.
    If determinant is less than 0, the roots are complex and different.

#include <stdio.h>
#include <math.h>

int main()
{
    double a, b, c, determinant, root1,root2, realPart, imaginaryPart;

    printf("Enter coefficients a, b and c: ");
    scanf("%lf %lf %lf",&a, &b, &c);

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

    // condition for real and different roots
    if (determinant > 0)
    {
    // sqrt() function returns square root
        root1 = (-b+sqrt(determinant))/(2*a);
        root2 = (-b-sqrt(determinant))/(2*a);

        printf("root1 = %.2lf and root2 = %.2lf",root1 , root2);
    }

    //condition for real and equal roots
    else if (determinant == 0)
    {
        root1 = root2 = -b/(2*a);

        printf("root1 = root2 = %.2lf;", root1);
    }

    // if roots are not real 
    else
    {
        realPart = -b/(2*a);
        imaginaryPart = sqrt(-determinant)/(2*a);
        printf("root1 = %.2lf+%.2lfi and root2 = %.2f-%.2fi", realPart, imaginaryPart, realPart, imaginaryPart);
    }

    return 0;
}