whats the axis of symmetry
Just to expand a little bit on Robert's answer:
x^{2}+6x + 6
The standard form of a quadratic function is y = ax^{2} +
bx + c
In your example 1x^{2}+6x +
6, a=1, b=6, and c=6
The axis of symmetry of a quadratic function is a line that passes
through the vertex (h,k) of the graph, and divides the graph
into two parts that are mirror images of each other. The x value
h = -b = -6 =-3
2a 2(1)
2a 2(1)
The axis of symmetry is x = -3.