The graph of the polynomial f(x) = ax^{2} + box + c is as shown in Fig. 2.20. Write the value of b^{2} – 4ac and the number of real zeros of f (x).

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

15