Complete the square by using the following form:
[tex](x+\frac{b}{2})^2 = x^2 +bx+(\frac{b}{2})^2 [/tex]
[tex]y = (x^2 -6x) +16 \\ \\ y = (x^2 -6x+9) + 16 - 9 \\ \\ y = (x-3)^2 + 7[/tex]
The vertex is at (3,7)
The squared term is positive so it opens up and vertex is a minimum.
