Use the f(x) button in the at the top of each text box in the activity editor to open the equation editor. Our equation editor uses LaTeX to format equations. For simple ones, you can just type, but there are lots of ways to make really good looking equations. Here's a pretty good cheat-sheet on how to make equations using LaTex

Examples:

\vec puts a vector arrow over the next character

\frac{a}{b} makes a nice a/b fraction

a^b and a_b make subscripts and super scripts

If you want more text in a subscript, put curly brackets around it:

F_{net}

\Delta (or any greek upper or lower) will make a nice ∆

So here's how to write Newton's Second Law

\vec a = \frac{ \Sigma \vec F}{m}

You could also write it as:

\vec a = \frac{ \vec F_{net}}{m}

Here's a familiar kinematics equation:

\Delta x = v_i t + \frac{1}{2} a t^2

Here's an important chemical reaction:

C_6H_{12}O_6 +6O_2 \rightarrow 6CO_2+6H_2O +\text{ATP}

There are two quirks with our LaTex editor:

1. If you type the expression with a LaTeX mistake (like forget to close parentheses) and then press save, it just won't show up. If you press the f(x) button again, you'll see your LaTeX and you can fix it.

2) If you make a typo, (like lower-case f for force) but your LaTeX is correct, then the equation will be rendered with typo in place, but you won't be able to edit it; you have to start all over again. For that reason I often copy the text out of the equation editor before I save and paste it somewhere (usually, right in the box where I'm working). That way, if I make a mistake I don't have to start all over again.

At some point we'll try to find a LaTex editor that doesn't have these quirks, but for now we must work with them. Luckily, you can make great looking equations with a little practice.