Question

Find the axis symetry of graph: f(x)=x^2+6x+8

Answer 1

vertex is what you need
use
\[x=-\frac{b}{2a}=-\frac{6}{2}=-3\] and
\[f(-3)=9-18+8=-1\] so vertex is
\[(-3,-1)\] and "axis of symmetry" is
\[x=-3\]