The two roots of a quadratic equation ax2 +bx+0 can be obtained using the following formula -b+vb2-4ac -b-Vb2-4ac and r) = b2-4ac is called the discriminant of the quadratic equation, and its value determines the number of roots as follows b2-4ac>0, two real roots: r1 and r2 b2-4ac 0, one real root: b2-4ac