How to use the graphing calculator to solve quadratic equations.
(I made a mistake on the last example, which I corrected through the annotations)

link to a video on how to solve quadratic equations by factoring or by using the quadratic formula:    • Solving Quadratic Equations  

link to a video on how to use the discriminant to determine how many and what kind of solutions a quadratic equation has:    • Quadratics  Discriminant