I’m not sure that there’s any serious misunderstanding, other than that x comes before y. I know that many people tell students to find the axis of symmetry by finding the value halfway between the x intercepts, in which case y=0. So the student does need to know that an axis is a line. The student was able to find the vertex, even though s/he put x and y backwards.

## One reply on “Axis of symmetry and vertex”

I’m not sure that there’s any serious misunderstanding, other than that x comes before y. I know that many people tell students to find the axis of symmetry by finding the value halfway between the x intercepts, in which case y=0. So the student does need to know that an axis is a line. The student was able to find the vertex, even though s/he put x and y backwards.