Use LaTeX (https://www.latex-project.org/) if you want to **write mathematical formulas** (simple or complicated).

- You can add formulas using the
**Text editor**from the resource Lesson

In **all test questions** highlighted below and in the answers of a Multiple Choice question and in the terms to be combine by a Combine pairs:

To write a mathematical formula with LaTeX, you need two things:

- First of all,
**use a precise delimiter**to indicate that you want to write a formula - Write the formula inside the delimiters, with
**appropriate commands**

**The delimiters by LaTeX**

Delimiters behave like parentheses: everything inside them will be interpreted as a command and **transformed into a formula**. The delimiters you can use on WeSchool to indicate a mathematical formula are two:

**the dollar**($... $)**the double dollar**($$... $$)

For example, writing $ x + y $ we will get:

What is the difference between the dollar and the double dollar? The dollar puts the formula **in line with the text**, while the double dollar places it in the center of the page.

**LaTeX commands**

To write a mathematical formula we can type it normally: some symbols (such as +, - and =, the letters of the alphabet and others) do not need a particular command to be entered. In practice, with LaTeX we can **write a literal expression without worrying**. Many other components of a mathematical formula, such as an exponent or a fraction, must be entered via a command. Below is a **list of the most frequently used commands** and an example of how to use them on WeSchool.

*Exponents and subscripts*

An **exponent** is obtained with the **caret character ^**, a **subscript** with the **underscore character _**. If what we have to put in the exponent or subscript is longer than a single character, we need to put it in **braces**. For example:

*Multiplications and fractions*

The multiplication symbol is obtained with the **\ times** command for a “**for**” symbol or with **\ cdot** for a **dot**. A **fraction**, on the other hand, is written using the **\ frac {N} {D} command**, where for **N** we will have the **numerator** and for **D** the **denominator**; of course, the numerator and denominator can themselves be complicated expressions. For example:

*Roots*

The square roots are indicated with the command **\ sqrt {R}**, where **R** is the **radicand**. If you want to indicate a root of a particular order, other than 2, the command is** \ sqrt [n] {R}** instead, with** n** the chosen index. For example:

The amount of symbols and commands that can be used with LaTeX is enormous. A list of the most used symbols can be found at this address. To check if the formula you wrote in LaTeX is correct, you can conveniently use this tool.