The general form of the quadratic equation is :
The discriminant is :
And the general solution is :
So, there are 3 situations for D
1. D = 0
So, the roots of a quadratic equation are two similar roots
2. D > 0
so, roots of a quadratic equation are two different roots
3. D < 0
so, roots of a quadratic equation are not real, two comlex roots