The axis of symmetry will be the vertical line given the equation x = h, where h is the x coordinate of the vertex. This value can be taken directly from an equation in vertex form: [tex]y=a(x-h)^2+k[/tex]
For example, given the equation [tex]y = -2(x+4)^2-8[/tex] the vertex is (-4, -8) so the a.o.s equation is x = -4
