The graph provided shows a downward-opening parabola, indicating that the function is quadratic, and it has a maximum point.

From observing the graph:

• The vertex of the parabola is located at $(0, 5)$.
• Since the vertex represents the highest point on this downward-facing parabola, the maximum value of the function occurs at the y-coordinate of the vertex.

Thus, the maximum value of the function is $5$.

Would you like further details or have any questions?

Here are 5 related questions to consider:

1. What is the general form of a quadratic function, and how does it relate to its vertex?
2. How can you find the vertex of a quadratic function algebraically?
3. What determines whether a parabola opens upwards or downwards?
4. How does the axis of symmetry of a parabola relate to its equation?
5. What role does the leading coefficient of a quadratic function play in its graph?

Tip: When analyzing a quadratic function graph, the vertex gives key information about the maximum or minimum value depending on the direction the parabola opens.