Maths — your first formula

Maths mode

This is what LaTeX is famous for. To write maths, switch into maths mode with dollar signs:

The equation $E = mc^2$ changed physics.

Text between $ ... $ is typeset as maths, right inside your sentence. This is inline maths.

$Inline maths sits in a sentence; display maths is centred on its own line$

Powers and indices

^ raises a superscript (a power); _ lowers a subscript:

$x^2$, $a_1$, and $x^2 + y^2 = r^2$

For more than one character, group them with braces: $x^{10}$ , $a_{i+1}$ .

Big, centred equations

For an important equation on its own line, use display maths \[ ... \]:

\[ a^2 + b^2 = c^2 \]

Now write your own inline formula in the task below.

Common mistakes

Inline maths goes in $...$ ; a missing closing $ breaks everything after it.
Display maths uses \[ ... \].

Replace the words with real maths. Write the area of a circle as an inline formula: $A = \pi r^2$ . The $ ... $ turns on maths mode, \pi is π, and ^2 is the power.

\documentclass{article}
\begin{document}
The area of a circle is A equals pi times r squared.
\end{document}

Click Run to compile and preview the PDF.

For an important equation, give it its own line with display maths \[ ... \]. Write Pythagoras' theorem: \[ a^2 + b^2 = c^2 \].

\documentclass{article}
\begin{document}
The most famous theorem in geometry:
\end{document}