Use the links for a help or practice.
http://www.regentsprep.org/regents/math/algtrig/ate3/discriminant.htm
https://www.khanacademy.org/math/algebra/quadratics/solving-quadratics-using-the-quadratic-formula/v/quadratic-formula-3
http://www.virtualnerd.com/algebra-1/quadratic-equations-functions/discriminant-quadratic-formula/discriminant/discriminant-no-solutions-example
HW: Complete yesterday's worksheet & bring your book tomorrow for the book 4.7 assignment.