In case you're not aware, Desmos is a free and amazing online graphing calculator students can use to explore mathematical ideas for themselves, with your guidance. It's a web app as well as an iOS and Android app. Students love it, for good reason.
There's a classroom activity they've created about parabolas here.
You could also just set up a parabola for them to play with, like here, and share the link.
Or if you just want a static figure, use Desmos to create the graph you want, and then take a screenshot. (Students may miss out on a lot with only a static figure, though!)
We embed a lot of Desmos calculators in Hype docs so we can include explanatory text and such and focus students' attention on a particular aspect. This gets a little more complicated, since we're using JavaScript on the backend to change things as we work our way through the doc, but if you're curious to explore the possibility I'm attaching a sample doc with an embedded calculator. (You're free to use their API to embed like this; their instructions are here.) You'll only see a blank box in Hype, but when you preview in a browser the fully functional calculator will appear.
If you don't want students to see (and hence be able to change) the Expressions list on the left, then in in the Hype doc go to the tab labeled 'loadCalc' and change line 7 from
expressions: true
to
expressions: false
Desmos-in-Hype.zip (96.3 KB)