Javascript throws fatal error when dividing functions

Something’s not working the way it seems like it should.

When I … was using desmos for my own math stuff, I defined the following functions in the order you see them from top to bottom

(Functions copy pasted below to help you replicate the bug)





I saw … everything stopped working, and an error appeared in the developer console of my browser. which read “ReferenceError: assignment to undeclared variable _XX” where XX is a number. Additional errors appeared that seemed like they were failing to connect to a bug reporting service called bugsnag, so I decided to make an account and manually report this.

But I expected … to see the function f(x)/g(x) be drawn. I was able to replicate this bug consistently by creating new tabs and trying this many times.

Here’s the link to the page, dashboard, or activity: This graph crashes desmos

And here are some screenshots or a video:

This forum is for the Desmos Activity Builder. Maybe try submitting this to

This should be fixed now. Thanks for the report. In the future, general calculator bugs can be reported to or

Thanks again!

Can confirm. It’s working now.