Answer:
y = 2
Explanation:
The axis of symmetry of a parabola is a line that divides the parabolic curve into two symmetric halves. It is a line of symmetry that passes through the vertex of the parabola.
Given equation of the parabola:

As the y-variable is squared, the given parabola is horizontal (sideways).
The standard form of a sideways parabola is:

where:
- Vertex = (h, k)
- Focus = (h+p, k)
- Directrix: x = (h - p)
- Axis of symmetry: y = k
Comparing the given equation with the standard equation, we can see that:
- h = -1
- k = 2
- 4p = 20 ⇒ p = 5
As the axis of symmetry is given by the formula y = k, the axis of symmetry of the given parabola is y = 2.