Hello guys, Welcome to Africa's Largest Video Search Engine, and you are watching Parabola vertex and axis of symmetry | Quadratic equations | Algebra I | Khan Academy. and this video is uploaded by Khan Academy at 2010-06-23T10:46:51-07:00. We are just promoting this video only for entertainment and educational purpose only. I hop you like our Video Search Engine. [dfoXtodyiIA]