Although the two outputs look quite similar, what is the advantage of using `$f^\prime$`

instead of `$f'$`

?

By the way, here is my code:

```
\documentclass{article}
\begin{document}
\[ f^\prime (x)=y \]
\[ f' (x)=y \]
\end{document}
```

## Best Answer

TL;DR:`'`

is a shorthand for`^{\prime}`

.`'`

is defined in`latex.ltx`

as active math character:The active

`'`

looks for following`'`

and puts them together as superscript,`a'''`

becomes`a^{\prime\prime\prime}`

. Thus using`'`

makes the input easier to write.