Question

look at this graph:
what is the maximum value of this function?

Explanation:

Step1: Identify vertex of parabola

The graph is a downward-opening parabola, with its vertex at the highest point. From the graph, the vertex is at $(0, 0)$.

Step2: Determine maximum value

For a downward-opening parabola, the vertex's y-coordinate is the maximum function value.

Answer:

$0$