Discriminant Worksheet (pdf) with Answer Key. Quadratic Equations practice! Example Questions Given the graph below determine a) the sign of the discriminant b) the number and nature of the roots. Find the discriminant to determine the number and nature of the roots of the equation x 2 + 7x + 6 = 0 Find all the values of a such that ax 2 + 5x + 3 = 0 has two real roots. Visual Aids Other Details This is a 4 part worksheet: