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Nielsen's Spiral


The Spiral with parametric equations

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

where $\mathop{\rm ci}\nolimits (t)$ is the Cosine Integral and $\mathop{\rm si}\nolimits (t)$ is the Sine Integral. The Cesàro Equation is
\kappa={e^{s/a}\over a}.
\end{displaymath} (3)

See also Cornu Spiral, Cosine Integral, Sine Integral


Gray, A. Modern Differential Geometry of Curves and Surfaces. Boca Raton, FL: CRC Press, p. 119, 1993.

© 1996-9 Eric W. Weisstein