Functions

Any characters put into a math environment are displayed in an italic math font. Some operators though, mostly functions, are typically written with other letter styles. To make this efficient, these characters are provided as commands, simply by putting a \ in front of the regular function name.

Here are all function commands in a nice table:

Some of these functions practically always have subscripts. For example, limits (\lim_) have one that tell us which variable is nearing what value. That’s what the underscore ( _ ) indicates in the table. You’ll see much more of it next chapter.

1$cos(x)^2 + sin(x)^2 = 1$ is wrong, instead use $\cos^2 x + \sin^2 x = 1$
2
3$lim_{x \rightarrow 2}$ is ugly, instead use $\displaystyle \lim_{x \to 2}$

If your favourite function isn’t listed, you can get the same result with

1\operatorname{yourOperator}{x}

If you want your custom operator to use those typical subscripts, use the star variation.

1$\operatorname*{pandaFunction}{x+y} = 2x + 2y$

Modulo

Modulo operators work the same, but they have two variations.

• \bmod expression simply prints mod expression
• \pmod expression adds space and parentheses around it

1$4 = 9 \bmod 5$ is true, but also $4 = 9 \pmod 5$