What's wrong with my TikZ?

I've just installed MacTeX-2019 on my MacBook. So I'm using TeXShop 4.27 which comes along.

I'm trying to execute the most basic GNUPLOT example: http://www.texample.net/tikz/examples/gnuplot-basics/

Here is the output I get:

What could possibly go wrong?

I've tried other examples that work well. But it looks like there is a specific problem with

\draw plot function

• \documentclass{article} \usepackage{tikz} \begin{document} \pagestyle{empty} \begin{tikzpicture}[domain=0:4] \draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9); \draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$}; \draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$}; \draw[color=red] plot ({\x},{\x}) node[right] {$f(x) =x$}; \draw[color=blue] plot ({\x},{sin(deg(\x))}) node[right] {$f(x) = \sin x$}; \draw[color=orange] plot ({\x},{0.05*exp(\x)}) node[right] {$f(x) = \frac{1}{20} \mathrm e^x$}; \end{tikzpicture} \end{document} – Schrödinger's cat Oct 14 at 12:51