Axis of Symmetry

A line of symmetry for a graph. The two sides of a graph on either side of the axis of symmetry look like mirror images of each other.

This is a graph of the parabola y = x^{2} – 4x + 2 together with its axis of symmetry x = 2.

The axis of symmetry is the red vertical line.

See also

Point of symmetry, axis of symmetry of a parabola, symmetric about the x-axis, symmetric about the y-axis