Question

Can you please explain step-by-step? I have male questions like this I need to be able to answer.

Answer 1

Vertex is the tip(sharpest) point of the curve. As you can see the tip of the curve has coordinates x = 1 and y = 3, vertex of curve is (1,3)

Answer 2

The vertex is the point that divides the graph symmetrically and occurs at a local maximum, minimum, or sometimes an inflection point.  In this case it is the global maximum at the point (1,3)