# C program to find roots of Quadratic Equation

Before going to the program first let us understand what is a *Quadratic Equation*?

**Quadratic Equation:**

A *Quadratic Equation* is any equation having the form:

where *x* represents an unknown, and *a*, *b*, and *c* represent known numbers such that *a* is not equal to 0. If *a* = 0, then the equation is linear equation, not quadratic.

For Example,

For more understanding you can check out the following link:

https://www.mathsisfun.com/algebra/quadratic-equation.html

## Program code to find roots of Quadratic Equation:

#include <stdio.h> #include<conio.h> #include <math.h> void main() { float a, b, c, determinant, r1,r2, real, imag; clrscr(); printf("Enter coefficients a, b and c: "); scanf("%f%f%f",&a,&b,&c); determinant=b*b-4*a*c; if (determinant>0) { r1= (-b+sqrt(determinant))/(2*a); r2= (-b-sqrt(determinant))/(2*a); printf("Roots are: %.2f and %.2f",r1 , r2); } else if (determinant==0) { r1 = r2 = -b/(2*a); printf("Roots are: %.2f and %.2f", r1, r2); } else { real= -b/(2*a); imag = sqrt(-determinant)/(2*a); printf("Roots are: %.2f+%.2fi and %.2f-%.2fi", real, imag, real, imag); } getch(); }

## Step by Step working of the above Program Code:

- First the computer reads the coefficients
**a , b**and**c**from the user. - Then it computes the value of
**determinant**using the formula.

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

- Then checks the determinant value is
**greater than , equal or less than to zero**using if else if ladder. - If the determinant value is
**greater than zero**, then root1 and root2 value is calculated using the formula:

r1=(-b+sqrt(determinant))/(2*a)

r2=(-b-sqrt(determinant))/(2*a)

- If the determinant value is
**equal to zero**, then root1 and root2 value is calculated using the formula:

r1=r2=-b/(2*a)

- If the determinant value is
**less than zero**, then root1 and root2 value is calculated using the formula:

real=-b/(2*a)

imag=sqrt(-determinant)/(2*a)

- Finally print the roots of the quadratic equation.

## Output:

### TO DOWNLOAD THE PROGRAM CODE :CLICK HERE