Question

The graph of a quadratic function has a domain of (-∞, ∞) and range of [4, ∞). In two or more complete sentences, explain how the given range of the function can help you to determine whether the graph opens up or down.

Answer 1

f(x)= -x^2+4

Explanation:

Answer 2

The range of the function indicates that the function has a vertex at y=4. The number on the left in the range notation is the lowest point, the number on the right is the highest point. Since the number on the right is ∞, the graph must open up and have a minimum at 4.

Hope this helps! :)