Question

look at this graph:
what is the equation of the axis of symmetry?

Explanation:

Step1: Identify parabola vertex

The vertex of the parabola is at $(0, 9)$, which lies on the axis of symmetry.

Step2: Determine vertical symmetry line

For a vertical parabola symmetric about the y-axis, the axis of symmetry is the vertical line passing through the vertex's x-coordinate.

Answer:

$x=0$