Your first question has been raised, so I won't say more. If you need me to say anything else, just ask.

Because I don't have draft paper now, I can't give a specific answer. Let me talk about the solution to the second problem.

Because m is on the axis of symmetry of parabola, O or A is symmetrical once along the axis of symmetry, connecting another point, and the intersection point with the axis of symmetry is M point.

I hope it helps you!

Please ask questions if you don't understand!

Hope to adopt!