Question

The vertex of a parabola is at (-2,4) and the x-intercepts are at -6 and 2. Determine the domain and range of the function.

a. D: all real numbers
R: all real numbers

b. D: -6 ≤ x ≤ 2
R: y ≤ 4

c. D: all real numbers
R: y ≤ 4

d. D:x ≤ 4
R: all real numbers

Answer 1

The correct answer is c)

D: all real numbers

R: y ≤ 4

Explanation:

We know this because a vertex is either a maximum or a minimum for the y value. Since the x-intercepts would be below the vertex, we know that the vertex must be a maximum.

Also, all parabolas will have a domain of all real numbers.