Question 867496
Solving the quadratic equation {{{ax^2+bx+c=0}}} using Completing the Square, you will find an irrational expression with the input of {{{b^2-4ac}}}.  THAT is the discriminant.


Look at <a href="http://www.algebra.com/tutors/Completing-the-Square-Using-Pictures.lesson?content_action=show_dev">Discussion to understand Completing the Square</a>