\documentclass[a4page]{article}
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\usepackage{lmodern}
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\usepackage{amsmath,amssymb}
\usepackage{fullpage}
\usepackage{graphicx}
\usepackage{pythontex}
\title{sympy on cocalc}
\author{cocalc}
\begin{document}
$2^{20}-1 = \pycon{2**20-1}$
\begin{sympyblock}
var('x, y, z')
z = x + y
f2 = sin(2*x**2).diff(x)
f2pi = f2.subs({x : pi})
\end{sympyblock}
$$f_2(\pi) = \sympy{f2pi} \approx \sympy{f2pi.n(32)}\ldots$$
\begin{sympyblock}
phi = Symbol(r'\phi')
h = Integral(exp(-phi**2), (phi, 0, oo))
\end{sympyblock}
\[\sympy{h}=\sympy{h.doit()}\]
\begin{pylabcode}
x = linspace(0, pi, 1000)
plt.plot(x, 2*sin(x**2), label='$2 sin(x^2)$')
plt.plot(x, cos(x), label='cos(x)')
savefig("plot.pdf")
\end{pylabcode}
\begin{center}
\includegraphics[width=0.85\textwidth]{plot.pdf}
\end{center}
\end{document}