1: How can you tell if the parabola opens upward or downward?

5: See the first slide for an illustration of each of these.

7: Calculate `h` ＝ -`b` divided by 2`a`, and then plug this value in as `x` to find `k`.

12: 2 times -3/4 is -6/4, and dividing by this is the same as multiplying by -4/6.

19: `b` is -12, not 12.

21: `k` is the minimum value if the parabola opens upward or the maximum value if the parabola opens downward.

31: Parabolas are symmetrical, so if you move the same distance to the right or to the left of the vertex, the new `y` value will be the same either way.

44: -`b`/2`a` is `h`, the `x`-coordinate of the vertex.