Question

Which of the following are true of a quadratic function whose discriminant is zero?

a) It has one real root.
b) It has two real and equal roots.
c) It has two complex roots.
d) It has no real roots.

Answer 1

A quadratic function whose discriminant is zero has two real and equal roots. The correct option is b.

Step-by-step explanation:

A quadratic function whose discriminant is zero has two real and equal roots.

If the discriminant of a quadratic equation is zero, it means that the equation has only one solution, and this solution will be a real number.

For example, if we consider the quadratic equation x^2 + 4x + 4 = 0, the discriminant is (4^2 - 4(1)(4)) = 0, and the equation can be factored as (x + 2)^2 = 0, which has one real root, x = -2. Therefore the answer is b.