For a quadratic equation **ax2+bx+c = 0** (where a, b and c are coefficients), it’s roots are given by following the formula.

The term **b2-4ac** is known as the discriminant of a quadratic equation. The discriminant tells the nature of the roots.

If the discriminant is **greater than 0**, the roots are real and different.

If the discriminant is **equal to 0**, the roots are real and equal.

If the discriminant is **less than 0**, the roots are complex and different.

**C++ Program to Find Roots of Quadratic Equation if/else**

```
#include<iostream>
#include<math.h>
using namespace std;
int main()
{
float root1,root2,a,b,c,d,imaginaryPart,realPart;
cout<<"Quadratic Equation is ax^2+bx+c=0";
cout<<"\nEnter values of a,b and c:";
cin>>a>>b>>c;
d=(b*b)-(4*a*c);
if(d>0)
{
cout<<"\nTwo real and distinct roots";
root1=(-b+sqrt(d))/(2*a);
root2=(-b-sqrt(d))/(2*a);
cout<<"\nRoots are "<<root1<<" and "<<root2;
}
else if(d==0)
{
cout<<"\nTwo real and equal roots";
root1=root2=-b/(2*a);
cout<<"\nRoots are "<<root1<<" and "<<root2;
}
else{
cout<<"\nRoots are complex and imaginary";
realPart = -b/(2*a);
imaginaryPart = sqrt(-d)/(2*a);
cout<<"\nRoots are "<<realPart<<"+"<<imaginaryPart<<"i and "<<realPart<<"-"<<imaginaryPart<<"i";
}
return 0;
}
```

**Output of Program**

Quadratic Equation is ax^2+bx+c=0

Enter values of a,b and c:5

5

5

Roots are complex and imaginary

Roots are -0.5+0.866025i and -0.5-0.866025i