Explaining your formulas

While formulas are a convenient way to describe mathematics, they cannot stand on their own in a report. The text should explain what is expressed by the formulas.

First of all, each new variable or constant should be defined when it is first introduced. What does it measure, and what is its unit? Likewise, a balance equation or a model deserves a careful introduction. How did you come up with this? Even calculations are easier to follow if they are accompanied by text to explain the more complicated steps. A straightforward addition or multiplication is easy enough to understand, but it can be kind to remind your reader of the antiderivative of the arctangent if you use this in your calculations.

When discussing your variables, constants or functions in your text, bear in mind that LATEX uses special formatting in math mode. To keep the look of your variable P(t) consistent, you should use math mode whenever you mention this variable: type $P(t)$ instead of just P(t).

Formulas: inline or displayed on a separate line?

You have seen three separate ways to display your mathematical formulas:

1. In the text as part of a sentence (inline formulas);
2. Displayed as an unnumbered equation on a separate line;
3. Displayed as a numbered equation on a separate line.

When formatting your text, take some time to think which of these options is most suitable for each formula. Displaying too many formulas in separate lines will give your page a very disjointed look. On the other hand, inline formulas can look rather cramped, and can be harder to read. As a rule of thumb, consider displaying a formula on a separate line in the following cases:

• The formula takes up more than one third of a line.
• The formula is a main result or model. Displaying it on a separate line will draw attention to it.
• You will refer back to this formula later. In this case, the formula should become a numbered equation.

Next, a page for questions about LATEX.