I lost my graphing calculator?

Ask the class if someone seen it. If u cant get it back from them, go seek out the janitor and ask him for one.

What I usually do is hop in the time machine and go back to the moment when I last remember having it and then go forward from there to see when/how I lost it. :)

I would just ask your classmates if they remember seeing it. Perhaps someone accidentally picked it up thinking it was theirs and now they have two. Also check with the school's lost and found in case it was dropped somewhere else.

It's late in the year, so perhaps you can finish the year without needing it. Or if you think you'll need it in the future, talk to your parents about what you need to do to get it replaced.

There are also graphing apps (like Desmos) that run on a smartphone, so you might be able to use something like that to get by.

millions of people have graduated with honors without any kind of calculator.

so your choices are:

do it by hand

buy a new one

use web sites that do graphing for you.