For ax2 +bx+c= 0 a x 2 + b x + c = 0, where a a, b b, and c c are real numbers, the discriminant is the expression under the radical in the quadratic formula: b2 −4ac b 2 − 4 a c. It tells us

What happens if the discriminant is zero? If the discriminant is equal to zero, this means that the quadratic equation has two real, identical roots. Therefore, there are two real, identical roots to