x = 3
Both sides of the parabola match up if you fold the graph in half on this line.
The equation to find axis of symmetry is:
x = -b/2a
So if you don’t have a graph to look at you can find this axis by using a parabolic equation in
y = ax^2 + bx + c form(this is like y = mx + b but for parabolas)
In axis of symmetry problems your answer will always be “x = _” if you just put the number you will get the answer wrong