Greek Letters and Maths Symbols in LaTeX for Beginners

The Greek alphabet, operators, relations and arrows, and how to find any symbol you cannot name. About twelve minutes.

Most symbols in maths are not on a keyboard. In LaTeX each one has a short name after a backslash, and the names are easier to remember than they look: most are the symbol's English name, or a short form of it.

Greek letters

A Greek letter is its name after a backslash: \alpha gives $\alpha$ , \theta gives $\theta$ , \pi gives $\pi$ .

\alpha, \beta, \gamma, \delta, \theta, \lambda, \mu, \pi, \sigma, \omega

Edit the LaTeX

Start the name with a capital letter for the capital: \Delta gives $\Delta$ , \Sigma gives $\Sigma$ , \Omega gives $\Omega$ . The capitals that look like Latin letters, such as the capital alpha and beta, have no command: type a plain A or B.

\Gamma, \Delta, \Theta, \Lambda, \Pi, \Sigma, \Phi, \Omega

Edit the LaTeX

A few letters have a second form, with var in front: \epsilon gives $\epsilon$ and \varepsilon gives $\varepsilon$ , \phi gives $\phi$ and \varphi gives $\varphi$ . Use whichever your course or textbook uses, and stick to it.

Operators

+ and - are typed as they are. The others have commands:

\times gives $\times$ , and \cdot a centred dot, $\cdot$ .
\div gives $\div$ .
\pm gives $\pm$ , and \mp gives $\mp$ .

(a \pm b)^2 = a^2 \pm 2ab + b^2

Edit the LaTeX

Relations

=, < and > are typed as they are. For the rest:

\leq gives $\leq$ and \geq gives $\geq$ (\le and \ge are shorter ways to write them).
\neq gives $\neq$ .
\approx gives $\approx$ , \equiv gives $\equiv$ , \sim gives $\sim$ , and \propto gives $\propto$ .

0 \leq x \leq 1, \quad y \neq 0

Edit the LaTeX

Arrows

\to gives $\to$ , for "tends to" and for functions between sets.
\Rightarrow gives $\Rightarrow$ and \iff gives $\iff$ , for implications.
\mapsto gives $\mapsto$ , for where a function sends a value.

f: x \mapsto x^2

Edit the LaTeX

\infty gives $\infty$ , which you will need next to arrows a lot: $x \to \infty$ .

When you cannot find a symbol

There are hundreds more. If you know what a symbol looks like but not its name, draw it to find its command, or look it up in the LaTeX symbols table.

Practise

$\alpha + \beta = \gamma$
$\Delta y = 3 \Delta x$
$\theta = \frac{\pi}{4}$
$(a+b)^2 \neq a^2 + b^2$
$x \geq 0$
$\pi \approx 3.14159$
$F \propto \frac{1}{r^2}$
$f: x \mapsto x^2$
$x \to \infty \Rightarrow \frac{1}{x} \to 0$

In short

Greek letters are their names after a backslash, with a capital first letter for a capital.
Operators: \times, \cdot, \div, \pm. Relations: \leq, \geq, \neq, \approx, \equiv.
Arrows: \to, \Rightarrow, \iff, \mapsto; and \infty for infinity.

Next, in lesson 5: brackets that grow to fit what is inside them.

Greek letters and symbols

Greek letters

Operators

Relations

Arrows

When you cannot find a symbol

Practise

In short

Would you rather write it by hand?