--- title: Axis of Symmetry of a Parabola --- ## Axis of Symmetry of a Parabola The axis of symmetry for a parabola is the line which perfectly bisects (or splits into two even parts) the parabola. This is the same as a vertical line drawn at the x-value of the parabola’s vertex. Knowing this, you can find the line of symmetry easily by using the vertex form of a quadratic (parabolic) equation: y = a(x-h)2+k In this form, the coordinates of a parabola’s vertex is given by (h,k), meaning the equation of the line of symmetry will be x=h.