Difference between revisions of "Sine integral"

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File:Si.png| Graph of $\mathrm{Si}$.
 
File:Si.png| Graph of $\mathrm{Si}$.
File:Domain coloring sine integral.png|[[Domain coloring]] of [[analytic continuation]] of $\mathrm{Si}$.
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File:Complexsiplot.png|[[Domain coloring]] of $\mathrm{Si}$.
 
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Revision as of 21:36, 23 May 2016

The sine integral is defined by $$\mathrm{Si}(z) = \displaystyle\int_0^z \mathrm{sinc}(t) \mathrm{d}t, \quad |\mathrm{arg} z|<\pi,$$ where $\mathrm{sinc}$ denotes the Sinc function.

Relationship to other functions

Theorem

The following formula holds: $$\mathrm{Ei}(ix)=\mathrm{Ci}(x)+i\mathrm{Si}(x),$$ where $\mathrm{Ei}$ denotes the exponential integral Ei, $\mathrm{Ci}$ denotes the cosine integral, and $\mathrm{Si}$ denotes the sine integral.

Proof

References

Videos

Laplace Transform of Sine Integral

References

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