# Exercise 9: Use equations

In this exercise, you will learn how to write and format mathematical equations in your TeachBook, both inline and as standalone blocks.

::::::{topic} Exercise objective
Can you write and format equations correctly in your book?
::::::

```{tip}
Using properly formatted equations makes mathematical expressions clearer and more professional. More details can be found in the [JupyterBook documentation](https://jupyterbook.org/en/stable/content/math.html).
```

## Writing equations

1. Open a new or existing Markdown file where you want to include an equation.
2. Start with a simple block equation using double dollar signs. Try adding the following equation in your Markdown file:

```md
$$ F_{res} = m \cdot a $$ 
```

3. Now, add an inline equation by enclosing the equation with single dollar signs. Try this example:


```md
The displacement can be found using the equation $s = v \cdot t$.
```

## Formatting mathematical symbols

4. In this step we will experiment with different LaTeX symbols. Use the following table and test each example in your Markdown file:


| Name | Script |
|---|---|
| Square root | `\sqrt{4}` | 
| Power | `^{2x}` | 
| Fraction | `\frac{2}{3}` | 
| Subscript | `_{gem}` |
| Superscript | `^{N}` | 
| Multiplication | `\cdot` | 

5. Extend this exercise by trying more advanced mathematical expressions:

| Name | Script | 
|---|---|
| Derivative | `\frac{\Delta f}{\Delta t}` | 
| Integral | `\int_a^b dx` | 
| Sine function | `\sin(x)` | 

6. Test your understanding by adding a new equation of your choice, ideally one that requires many LaTex symbols!

7. When you are ready, commit your changes to the repository by clicking on the green `Commit changes` button.

8. Add a commit message.

9. To see your changes, go to {octicon}`play;1em` `Actions` - The most recent workflow run `overview.md / the commit message of the commit you just made` - Wait for it to finish - In the summary, click on the link of your book shown in the table `Branches deployed` and under `Primary book at root` (getting bored of waiting? There'll be exercising on doing this locally which prevents you from waiting).

10. Do you see your change? If you don't see it click `CTRL`+`F5`/`Control`+`F5`to refresh the page.


```{admonition} Check your understanding
:class: note

Before moving on to the next exercise, make sure you understand the following:
- What is the difference between inline and block equations?
- How do you use LaTeX formatting for different mathematical symbols?

```