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Log Sine Function


The log sine function, also called the logsine function, is defined by

 S_n=int_0^pi[ln(sinx)]^ndx.
(1)

The first few cases are given by

S_1=-piln2
(2)
S_2=1/(12)pi^3+pi(ln2)^2
(3)
S_3=-1/4pi^3ln2-pi(ln2)^3-3/2pizeta(3),
(4)

where zeta(z) is the Riemann zeta function.

The log sine function is related to the log cosine function by

 S_n=2C_n
(5)

and the two are equal if the range of integration for S_n is restricted from 0 to pi to 0 to pi/2.


See also

Clausen's Integral, Log Cosine Function, Log Gamma Function

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References

Boros, G. and Moll, V. "The Logsine Functions." §12.5 in Irresistible Integrals: Symbolics, Analysis and Experiments in the Evaluation of Integrals. Cambridge, England: Cambridge University Press, pp. 202 and 245-249, 2004.

Referenced on Wolfram|Alpha

Log Sine Function

Cite this as:

Weisstein, Eric W. "Log Sine Function." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/LogSineFunction.html

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