What does the axis of symmetry tell you about a graph's vertex?

Question

I'm having a hard time answering this question, would someone please help me understand what the axis of symmetry tells you about a graph's vertex? 

Answer 1

The axis of symmetry is the reference line where the graph is symmetrical.  The vertex is the point where the graph turns direction at the reference line.  So the vertex has a coordinate of x or y, depending on the equation of axis of symmetry. 

 

If axis of symmetry is x = C, then the vertex is (C, y).

 

If axis of symmetry is y = C, then the vertex is (x, C).