Help Please.

It is a parabola....

if 'a' is positive it is open upwards like a bowl

if 'a' is negative it is open downward like a dome

You know you asked this EXACT SAME QUESTION a couple of days ago!!!!!!????  AND it was answered...........

    Why post it AGAIN?

Because my teacer asked me again

....and you didn't learn the answer?   You didn't remeber asking the question just a day or two ago?

You didn't want to take the time to look up the answer that was given then?

  Are we just doing every bit of your homework?  Are you learning anything?  Are you TRYING to learn how the answers are derived? 

Guest please stop..I did not remembered. But thank you all for answering it