# Graph of a Quadratic Equation

f(x) = ax2 + bx + c = 0, where a â‰  0, and b and c are real coefficients.

As is obvious from the above graphs, when D>0, there are two points at which this curve is intersecting X-axis. And we also know that there are two distinct values of x which satisfy f(x).

When D=0, there is only one point at which this curve is intersecting X-axis, and there is only one distinct value of xwhich satisfies f(x).

When D<0, there is no point at which this curve is intersecting X-axis. So, there are no real values of x which can satisfy f(x).