Desmos cannot currently render Matrices in a Note. The following Matrix | Component screen allows you to write any Matrix up to dimensions 3x4, including Augmented Matrices, for use in your Activities.
It uses a user-friendly table-based input format and flexes and breathes according to the location and number of matrix entries. Assumes equations written as: Ax+By+Cz=D. Looks like this:
Features:
- No dependencies
- No deprecated features
- Can be used with whatever correctness scheme you have in mind
- It “just works” with little to no fiddling on your end
It heavily abuses some Latex trickery to render the Matrix in a user-friendly manner. I hope people find it of use until/if Desmos supports cases for true Matrix authoring.