b 2 – 4ac = 0,
Two
The given quadratic equation touches the x - axis at only one point.
The root of the quadratic equation is equal and real because if the quadratic equation has two distinct roots, then the graph touches the x - axis at two points.
As we know that the roots are real and equal if the value of discriminant is zero,
So, b 2 – 4ac = 0