Checkpoint: Parabolas Solution

How can you determine the direction of the parabola from a given equation? Explain.

Sample: One way to determine the direction is to identify the variable to the second power. If the equation includes $x^{2},$ the parabola opens up/down. If the equation includes $y^{2},$ the parabola opens right/left.

Graph.
$x = - 2 {(y + 1)}^{2}$

a = –2 (opens left)
h = 0
k = –1

vertex: $(0, - 1)$

Note

Q: What direction will the parabola open? Explain.

A: The parabola will open left because the parent graph is $x = y^{2}$ and $a = - 2 .$