Parabolas
Opens Vertically
The equation of a parabola with vertex at (h, k) that opens in the "y-direction" is y = a(x - h)2 + k. The direction of opening is determined by the value of a. If a < 0, it will open down. If a > 0, it will open up. This form is exactly the same as a translated parabola from previous lessons. These parabolas will have the following properties:Focus:
![OpensV1-1 OpensV1-1](https://claregladwinresd.glk12.org/pluginfile.php/975/mod_book/chapter/464/Conic_Sections/images/OpensV1-1.png)
Directrix:
![OpensV1-2 OpensV1-2](https://claregladwinresd.glk12.org/pluginfile.php/975/mod_book/chapter/464/Conic_Sections/images/OpensV1-2.png)
Axis of symmetry:
![OpensV1-3 OpensV1-3](https://claregladwinresd.glk12.org/pluginfile.php/975/mod_book/chapter/464/Conic_Sections/images/OpensV1-3.png)