What is the axis of symmetry?

Question

In World War I, Germany used long-range siege guns. A mortar fired from one of these guns travels in a parabolic arc. The mortar lands just over 130 kilometers from where it was fired and reaches a maximum height of 43 kilometers. Its trajectory is given by a = 0.01. What is the axis of symmetry? Round to the nearest hundredth of a kilometer.

Answer 1

The vertex is at 65 kilometers (half the way). So the axis of symmetry is x = 65.