# How to use partial derivate in my code?

**URL:** https://discourse.julialang.org/t/how-to-use-partial-derivate-in-my-code/134176
**Category:** General Usage
**Tags:** question
**Created:** [November 28, 2025, 2:10am UTC](https://discourse.julialang.org/t/how-to-use-partial-derivate-in-my-code/134176 "2025-11-28T02:10:45Z")
**Posts on this page:** 1
**Showing post:** 4

<div class="post-metadata">

### Author: ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [November 28, 2025, 4:47am UTC](https://discourse.julialang.org/t/how-to-use-partial-derivate-in-my-code/134176/4 "2025-11-28T04:47:01Z")

</div>

> [@Mr.Fool](#):
>
> I want to use the partial marked red in the figure to write my own code.

If you just want to know how to _type_ it, the REPL help tells you:

```julia-auto
help?> ∂
"∂" can be typed by \partial<tab>

```

This kind of tab completion is supported in the REPL and can also be configured in most modern editors.

But by default, `∂` doesn’t have any definition in Julia, and is just another possible identifier, like `x` or `f`. It is up to you to assign a meaning to it.

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