A formula that “looks right” in Markdown notes only means your notes app rendered it. Slack, Discord, Google Docs, and homework boxes often will not. Do not leave the formula as characters in chat for AI to finish. Pull that one expression onto a preview page, you check the render, then decide on an export — what other people receive is a formula, not
$...$.
Why does a formula look fine in notes and become code when I send it?
Because rendering happens inside the notes app you are using, and does not travel with copy. Obsidian, Typora, and VS Code preview turn $E=mc^2$ into math. Slack, Discord, a Canvas text box, most email — they treat it as ordinary characters. The other person gets dollar signs and backslashes.
The formula is not wrong. The same source is an expression on a page that runs KaTeX / MathJax, and code on a plain-text channel. Students turning in homework, dropping a derivation in a course channel, pasting a key equation into Google Docs, all hit this.
Another common miss is dumping the whole note (headings, lists, several $…$ runs) into a “formula tool.” A single-expression box truncates or errors. If the page says this looks like Markdown body with several formulas, you picked the wrong shape: extract the one you need to send.
Checking a homework formula on the spot, and how to drop an image into Word / PowerPoint, are in I can’t write LaTeX — how do I check an AI formula immediately? and Insert a math formula in Word, PowerPoint, or similar. This article only covers “the notes already have the expression; I need to send it to someone whose app does not render math.”
How do I render one formula as an image before I send it?
Extract that one expression, preview it alone, then export — do not copy source from notes straight into a chat box. If you still cannot write the formula, have your current AI output the expression body only (no $, no $$, no whole Markdown note) onto a page with a live preview. Open Markdown LaTeX formula, turn on Connect your AI.
One round can look like this — AI speeds the commands; you decide pass/fail on the preview:
You:
The quadratic formula. Expression body only — no dollar signs, no whole note. Write it to the current formula page so I can check the preview.
Assistant:
Written to formula.tex. If the preview says render succeeded, pick PNG for Slack or SVG for slides. If it errors, send the red text back and I will only fix this one expression.
Do not imagine whether the formula is right — chat on the left, an arrow to the formula page on the right, preview already showing the expression:
Preview pass is what counts as an export; subscript meaning still needs your eye. Cowriting here is not letting the model hand you a pile of source in chat and stop. Setup: How do I let my current AI operate a web tool?.
Unclosed braces, \Sigma mixed with \sigma — the page marks the location. Do not ask the model to “rewrite the whole notes section while it is here”; you will hit a cap around five thousand characters.
After the preview passes, have the assistant list PNG and SVG; you pick one, then trigger the browser download:
| Where you are sending it | Safer format | Why |
|---|---|---|
| Slack / Discord, an LMS upload box | PNG | Sent as an image; the other person needs no math engine |
| Google Slides, Keynote, a zoomable deck | SVG | Stays sharp when enlarged |
| Still in Obsidian for yourself, still editing | Keep the source in the note | Images are hard to edit; source stays editable |
| Word, a CMS that rejects SVG | PNG | Details in the insert-into-documents article |
Setup: How do I let my current AI operate a web tool?. If you see \documentclass or \section, that is a paper project — switch to the LaTeX editor, do not force it into a single-formula box.
KaTeX covers everyday homework and notes math, not full TeX. TikZ figures, rare packages, and very long derivations will not fit a single preview; compile a full document or split into several images.
When must I export an image, and when can I still paste source?
When the other person’s app does not render LaTeX, you need an image. When they use the same kind of notes app, or the platform documents math support, you can keep pasting source.
| Situation | Suggestion | Why |
|---|---|---|
| Course Slack, a parent group chat | Export PNG | The receiving end is chat, no formula engine |
| Homework that only takes images or Word | PNG into the doc, or submit the image | Source will be treated as body text |
| Keep writing in Obsidian / Typora | Leave $...$ in the note |
Local render, fast to edit |
| Same expression stays in notes and goes to chat | Source in the note, plus one exported image | Each place uses its own form |
| The model gave a whole Markdown section with prose | Cowrite the body in the Markdown editor | The formula page accepts one expression at a time |
Boundaries: the connection follows the tab; close the page and it drops. A single-formula page does not do bibliographies or cross-references. AI can speed “from the prompt to the commands.” Whether a subscript is right in the subject still needs you to look at the preview before you send — a wrong image in a channel is harder to retract than a notes edit.
Wrap-up
A formula that looks right in notes only means local render worked. Before Slack, Docs, or an LMS, extract that one expression, preview it on the spot, then send it as an image. Do not leave the formula as characters for the model to finish in chat. Taking $$ or a whole Markdown note into the renderer is the usual wrong shape. Source stays for you to keep editing; images are for people whose apps cannot render.