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Sici Spiral

\begin{figure}\begin{center}\BoxedEPSF{SiciSpiral.epsf scaled 700}\end{center}\end{figure}

The spiral

$\displaystyle x$ $\textstyle =$ $\displaystyle c\mathop{\rm ci}\nolimits t$  
$\displaystyle y$ $\textstyle =$ $\displaystyle c(\mathop{\rm si}\nolimits t-{\textstyle{1\over 2}}\pi),$  

where $\mathop{\rm ci}\nolimits (t)$ and $\mathop{\rm si}\nolimits (t)$ are the Cosine Integral and Sine Integral and $c$ is a constant.

See also Cosine Integral, Sine Integral, Spiral


von Seggern, D. CRC Standard Curves and Surfaces. Boca Raton, FL: CRC Press, pp. 204 and 270, 1993.

© 1996-9 Eric W. Weisstein