Tikz/Pgfplots - Can not plot trig functions with a horizontal shift

Question

I am trying to plot an acos graph using tikz and pgfplots where the function should receive x-2 as an argument to plot the graph of acos(2-x) which gives the acos(x) function a h-shift to the right and a reflection on the y-axis

\begin{tikzpicture}
\begin{axis}[
    smooth,
    no markers,
    axis lines=center,
    xlabel=$x$,
    ylabel=$y$,
    xmin=-1.0, xmax=1,
    ymin=-0.2 , ymax=180,
]

\addplot[name path=A, domain=-1:1, samples=101]{acos(2-x)};

However, I always get the following error when compiling:

Missing number treated as zero
Illegal unit of measure (pt inserted)

Adding r at the end of the 2-x does not help either.

Answer 1

The problem with your code is that it asks pgf to compute acos of 3 and other values that are outside of its domain. Another problem is that you present only fragments. Here is a simple way to shift the graph to the right and reflect it at the vertical axis: instead of \addplot <function(x)>; use \addplot (<hshift-x,{function(x)});.

\documentclass{article}
\usepackage{pgfplots}
\usepgfplotslibrary{fillbetween}
\pgfplotsset{compat=1.16}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
    smooth,
    no markers,
    axis lines=center,
    xlabel=$x$,
    ylabel=$y$,
    ymin=-0.2 , ymax=180,
]
\addplot[dashed, domain=-1:1, samples=101] {acos(x)};
\addplot[name path=A, domain=-1:1, samples=101] (2-x,{acos(x)});
\end{axis}
\end{tikzpicture}
\end{document}

The dashed curve is just the untransformed acos function to show that this work.