I'm trying to draw something like this:
And I probably should use a 3D-plot as shown here but it seems to be an overkill solution in my case. So I wonder if there is a better way to draw ellipses than mine solution:
\documentclass[12pt, border=0.5mm]{standalone}
\usepackage{graphicx}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage[sc]{mathpazo}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.11}
\begin{document}
\begin{tikzpicture}[x=1mm, y=1mm]
\begin{axis}[
axis x line=center,
axis y line=center,
xlabel=$x$,
ylabel=$y$,
xmin=-0.2,
xmax=7.5,
ymin=-1.2,
ymax=1.2,
xlabel style={below right},
ylabel style={above left},
xticklabel=\empty,
ytick={-1, 1},
height=80mm,
width=100mm,
]
\addplot[peter_river, line width=0.25mm, mark=none, samples=150, domain=0:7] {1/x};
\addplot[peter_river, line width=0.25mm, mark=none, samples=150, domain=0:7] {-1/x};
\node[font=\small, anchor=east] at (axis cs:7, 1) {$\pi\cdot\displaystyle\int_{1}^{\infty}{\bigg(\displaystyle\frac{1}{x}\bigg)^2}dx$};
\draw[] (axis cs:2, 0) ellipse (20 and 10);
\draw[] (axis cs:1, 1) -- (axis cs:2, 1);
\draw[] (axis cs:1, -1) -- (axis cs:2, -1);
\begin{scope}
\clip[] (axis cs:1, -1) rectangle (axis cs:1.5, 1);
\draw[dashed] (axis cs:1, 0) ellipse (20 and 10);
\end{scope}
\begin{scope}
\clip[] (axis cs:1, -1) rectangle (axis cs:0.5, 1);
\draw[] (axis cs:1, 0) ellipse (20 and 10);
\end{scope}
\draw[] (axis cs:4, 0) ellipse (10 and 5);
\draw[] (axis cs:2, 0.5) -- (axis cs:4, 0.5);
\draw[] (axis cs:2, -0.5) -- (axis cs:4, -0.5);
\begin{scope}
\clip[] (axis cs:2, -1) rectangle (axis cs:2.5, 1);
\draw[dashed] (axis cs:2, 0) ellipse (10 and 5);
\end{scope}
\begin{scope}
\clip[] (axis cs:2, -1) rectangle (axis cs:1.5, 1);
\draw[] (axis cs:2, 0) ellipse (10 and 5);
\end{scope}
\draw[] (axis cs:4, 0.25) -- (axis cs:7, 0.25);
\draw[] (axis cs:4, -0.25) -- (axis cs:7, -0.25);
\begin{scope}
\clip[] (axis cs:4, -1) rectangle (axis cs:4.5, 1);
\draw[dashed] (axis cs:4, 0) ellipse (5 and 2.5);
\end{scope}
\begin{scope}
\clip[] (axis cs:4, -1) rectangle (axis cs:1.5, 1);
\draw[] (axis cs:4, 0) ellipse (5 and 2.5);
\end{scope}
\node[font=\small] at (axis cs:1.5, 1.1) {$\pi$};
\node[font=\scriptsize] at (axis cs:3, 0.65) {$\displaystyle\frac{\pi}{2}$};
\node[font=\scriptsize] at (axis cs:5.5, 0.4) {$\displaystyle\frac{\pi}{4}$};
\draw[-stealth] (axis cs:0.5, 0.05) to[out=90, in=-20] (axis cs:0.35, 0.15)
to[out=200, in=90] (axis cs:0.2, 0)
to[out=270, in=160] (axis cs:0.35, -0.2)
to[out=20, in=270] (axis cs:0.5, -0.05);
\end{axis}
\end{tikzpicture}
\end{document}



axis cs:to the ellipse coordinates to run it in previous versions). – Rmano May 23 '16 at 11:03