The discriminate of any equation in any degree plays an important role in determining the roots of that equation. In case of a quadratic equation with a positive discriminate, the roots are real while a 0 discriminate indicates a single real root. A negative discriminant indicates imaginary (complex number format) roots. As shown in the video (along with a plot of the aforesaid equation), the discriminant of the equation a(x^2) + bx + c is (b^2) - 4ac. This is a straightforward way of calculating the discriminant. This same discriminant can be used to even find the roots of the quadratic equation.
Start your career in Graphic Design with the WonderHowTo's Beginners’s Guide to Photoshop Course