Here's a simple C program that can solve a quadratic equation of form ax^2 + bx + c = 0 using the quadratic formula:

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

int main() {
    double a, b, c, discriminant, root1, root2;

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

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

    if (discriminant > 0) {
        root1 = (-b + sqrt(discriminant)) / (2 * a);
        root2 = (-b - sqrt(discriminant)) / (2 * a);
        printf("Two real and distinct roots: %.2lf and %.2lf\n", root1, root2);
    } else if (discriminant == 0) {
        root1 = -b / (2 * a);
        printf("One real and equal root: %.2lf\n", root1);
    } else {
        double realPart = -b / (2 * a);
        double imaginaryPart = sqrt(-discriminant) / (2 * a);
        printf("Two complex roots: %.2lf + %.2lfi and %.2lf - %.2lfi\n", realPart, imaginaryPart, realPart, imaginaryPart);
    }

    return 0;
}
```

This program will ask for the coefficients a, b, and c, then calculate the roots based on the discriminant. It will display the roots as real and distinct, real and equal, or complex, depending on the value of the discriminant.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence