# Equation formatting

from Red Blob Games
29 Mar 2019

Here I’m using both color and tables (using the table tag instead of css grid), with labels for the symbols:

 $$\frac{dR}{dt}$$ = $$\alpha$$ $$\cdot$$ $$R$$ $$-$$ $$\beta$$ $$\cdot$$ $$R$$ $$\cdot$$ $$F$$ rate of changeof rabbits is birth rate times rabbits minus kill rate times rabbits times foxes

This is highly distracting. Describing the basic symbols is overkill for an audience that’s reading about differential equations! Let’s drop those:

 $$\frac{dR}{dt}$$ = $$\alpha$$ $$\cdot$$ $$R$$ $$-$$ $$\beta$$ $$\cdot$$ $$R$$ $$\cdot$$ $$F$$ rate of changeof rabbits birth rate rabbits kill rate rabbits foxes

There are still too many colors. Let’s use color only for rabbits:

 $$\frac{dR}{dt}$$ = $$\alpha$$ $$\cdot$$ $$R$$ $$-$$ $$\beta$$ $$\cdot$$ $$R$$ $$\cdot$$ $$F$$ rate of changeof rabbits birth rate rabbits kill rate rabbits foxes

An alternative to describing the symbols is to describe the expressions. Chris Olah recommends left alignment and extra whitespace.

 $$\frac{dR}{dt}$$ $$=$$ $$\alpha \cdot R$$ $$-$$ $$\beta \cdot R \cdot F$$ rate of change rabbits born rabbits die

I haven’t quite figured out the TeX to make explanations appear underneath the parts of the formula. These don’t line up:

$\underbrace{\frac{dR}{dt}}_\text{rate of change} = \underbrace{\alpha \cdot R}_\text{rabbits born} - \underbrace{\beta \cdot R \cdot F}_\text{rabbits die}$

Also see Shan Carter’s beautiful version, which has both labels for variables and labels for expressions, and also uses color! I haven’t tried to reproduce this yet. I think it uses CSS grid with borders on an empty cell to create the bracket.

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