h, or x-coordinate of vertex occurs where 
k, or y-coordinate of vertex:  
With (h, k) being (- 6, 4), we get: ============
                                    |   x    y |
                                    |- 10      |
                                    |-  8      |
                                    |-  6  - 4 |
                                    |-  4      |
                                    |-  2      |
                                    ============
Populating the y-slots above or below the vertex, 
              (- 6, - 4) gives us:  ============
                                    |   x    y |
                                    |- 10   12 |
                                    |-  8    0 |
                                    |-  6  - 4 |
                                    |-  4      |
                                    |-  2      |
Below the VERTEX, we have the SAME y-coordinates 
we just found, ABOVE. This gives us:============
                                    |   x    y |
                                    |- 10   12 |
                                    |-  8    0 |
                                    |-  6  - 4 |
                                    |-  4    0 |
                                    |-  2   12 |  
                                    ============
You now have the vertex, (- 6, - 4), plus 2 points on EITHER side of the vertex. 

In addition, if you look you'll see the solutions to the quadratic: the points on the x-axis, or the roots,
which are: - 8, from point (- 8, 0), and - 4, from the point, (- 4, 0)