Recall the general form: ax² +bx +c = 0
You should be familiar with the Quadratic Formula. The Discriminant is used to predict the nature of the roots of an equation, it is the radicand in the formula.
[tex]\boxed{discriminant = b^{2} -4ac}[/tex]
Two distinct real roots if discriminant >0.
Equal roots if discriminant = 0.
Two distinct unreal(imaginary) roots if discriminant <0.