# Program to find Roots of a Quadratic Equation

In this post You’ll be learning how to write a program for finding out the roots of a quadratic equation in various programming language.

Standard form a quadratic equation is

ax2 +bx + c=0 where a, b, c are real numbers and a!=0

### Shridhara’s Formula

According to Shridhara’s formula

b2-4ac is the value of the term discriminant in quadratic equation.

Value of discriminant defines nature of roots.

1. If value of discriminant is greater than 0 then equation has real roots.
2. Discriminant is 0 then equation has equal and real roots.
3. If the discriminant is less than `0`, the roots are complex and different.

### C Program to Find Roots of a Quadratic Equation

```#include <math.h>
#include <stdio.h>
int main() {
double a, b, c, discriminant, root1, root2, realPart, imagPart;
printf("Enter coefficients a, b and c: ");
scanf("%lf %lf %lf", &a, &b, &c);

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

// condition for real and different roots
if (discriminant > 0) {
root1 = (-b + sqrt(discriminant)) / (2 * a);
root2 = (-b - sqrt(discriminant)) / (2 * a);
printf("root1 = %.2lf and root2 = %.2lf", root1, root2);
}

// condition for real and equal roots
else if (discriminant == 0) {
root1 = root2 = -b / (2 * a);
printf("root1 = root2 = %.2lf;", root1);
}

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

return 0;
}
```

### Output

```Enter coefficients a, b and c: 2.3
4
5.6
root1 = -0.87+1.30i and root2 = -0.87-1.30i```

In this program, the `sqrt()` library function is used to find the square root of a number. To learn more, visit: sqrt() function. Read more about programming here