The command `\pgfmathparse{asin(1/\x)}`

yields for each `\x`

in the range of 125 to 142 the same value, whereas `\pgfmathparse{1/\x}`

yields the much more precise values for each `\x`

. Is the ArcSin function of PGF that imprecise?

What can i do to get more precise results?

MWE:

```
\documentclass[11pt]{minimal}
\usepackage{tikz}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}
\foreach \x in {120,121,...,150}
{
\pgfmathparse{1/\x}\let\fraction\pgfmathresult
\pgfmathparse{asin(\fraction)}\let\angle\pgfmathresult
\node at (0, \x/2-60) {\x, \fraction, \angle};
}
\end{tikzpicture}
\end{document}
```

## Best Answer

There are different math engines that can be used with pgf/TikZ.

## Library

`fixedpointarithmetic`