Answer:
maximum
Explanation:
Concepts
The vertex of a graph represents the turning point in a parabola.
Example: The graph shown in your question first steadily increases, but then at the point (1,3), it begins to go down. The point (1,3) is called the vertex in this case because it symbolizes the turning point.
Application
We are asked to determine if the vertex of this graph is a maximum or minimum. If the vertex is maximum, it's the highest point on the graph. If it's the minimum, it's the lowest point on the graph. Using your stunning eyes, you can see that the vertex is the highest point on the graph, making the answer maximum.