If the discriminant of a quadratic equation is zero, the roots are

1. When $b^2-4ac=0$, the two roots coincide. 2. So the roots are **real and equal** (a repeated root). 3. Both roots equal $-\dfrac{b}{2a}$. _Source: Karnataka SSLC (KSEEB) Class 10 Mathematics, Ch10 'Quadratic Equations', §10.4_