Mit TikZ so:
%%%%%%%%%%%%%%%%
%Funktion
%%%%%%%%%%%%%%%%
%F = C - d * Cos(3/2*(theta - 60))
%F: gezielte Funktion
%C: die blaue Kurve
%d: der Unterschied zw. blauen und roten Kurven
\def\CWert{0.73}
\def\dWert{2.45}
\def\phiWert{60}
\def\omegaWert{1.5}
\draw[color=red, thick] plot[domain=0:1.25*pi, samples=200]
(
{\x},
{\CWert - \dWert*cos(\omegaWert*(\x - \phiWert) r)} % r für "radiant"
)
node[above=1cm]{$F(x) = C-d\cdot\cos\bigl(\frac32 (x - 60^\circ)\bigr)$}
;
![alt text][1]
\documentclass{article}
\usepackage[ngerman]{babel}
\usepackage{tikz}
\usetikzlibrary{matrix}
\begin{document}
\begin{tikzpicture}[scale=0.8, transform shape]
\draw[->] (-3,0) -- (4.2,0) node[right] {$x$};
\draw[->] (0,-3) -- (0,4.2) node[above] {$y$};
\draw[<->] (0.1,2.9) -- (0.1,3.6);
\draw[densely dotted] (0,0) -- (0,3.85);
\draw[densely dashed] (0,0) -- (0,3.85);
\draw[densely dotted, rotate=120] (0,0) -- (0,3.60);
\draw[densely dotted, style=help lines, rotate=60] (0,0) -- (0,3.85);
\draw[densely dashed, style=help lines, rotate=60] (0,0) -- (0,3.85);
\draw[thick,blue,opacity=0.5] ([shift=(90:103pt)]0,0) arc (90:210:103pt);
\draw[red,dashed,opacity=0.5] ([shift=(90:82pt)]0,0) arc (90:210:82pt);
\draw[->,black,opacity=0.5] ([shift=(90:108pt)]0,0) arc (90:150:108pt);
\node (a) at (0.3,3.3) {$d$} node (b) at (-2,3.5) {$\theta$};
%%%%%%%%%%%%%%%%
%Funktion
%%%%%%%%%%%%%%%%
%F = C - d * Cos(3/2*(theta - 60))
%F: gezielte Funktion
%C: die blaue Kurve
%d: der Unterschied zw. blauen und roten Kurven
\def\CWert{0.73}
\def\dWert{2.45}
\def\phiWert{60}
\def\omegaWert{1.5}
\draw[color=red, thick] plot[domain=0:1.25*pi, samples=200]
(
{\x},
{\CWert - \dWert*cos(\omegaWert*(\x - \phiWert) r)}
); r)} % r für "radiant"
)
node[above=1cm]{$F(x) = C-d\cdot\cos\bigl(\frac32 (x - 60^\circ)\bigr)$}
;
\end{tikzpicture}
\end{document}
[1]: http://texwelt.de/wissen/upfiles/55555555_54.png
