Answer:
the equation of the axis of symmetry is
Step-by-step explanation:
Recall that the equation of the axis of symmetry for a parabola with vertical branches like this one, is an equation of a vertical line that passes through the very vertex of the parabola and divides it into its two symmetric branches. Such vertical line would have therefore an expression of the form: , being that constant the very x-coordinate of the vertex.
So we use for that the fact that the x position of the vertex of a parabola of the general form: , is given by:
which in our case becomes:
Then, the equation of the axis of symmetry for this parabola is: