Question

Which of the following is true of the discriminant for the graph below?

A. It is undefined
B. It is negative.
C. It is zero
D. It is positive

Answer 1

Option C. It is zero

Explanation:

The graph represents a quadratic equation

The quadratic equation has the form ⇒a x² + b x + c

The discriminant of the quadratic equation is D = b² - 4ac

From the discriminant of the quadratic equation, we can know the type of roots of the quadratic equation.

1. If D > 0 ⇒ Two real roots.
2. If D = 0 ⇒ one real roots
3. If D < 0 ⇒ Two imaginary roots.

The roots of the quadratic equation are the x-intercepts of the function.

As shown at the figure, the quadratic equation has only one point of intersection with the x-axis

So, the function has only one root ⇒ D = 0

So, the discriminant of the quadratic equation = 0

The answer is option C. It is zero