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ExpIntegralEi






Mathematica Notation

Traditional Notation









Gamma, Beta, Erf > ExpIntegralEi[z] > Series representations > Generalized power series > Expansions on branch cuts > For the function itself





http://functions.wolfram.com/06.35.06.0023.01









  


  










Input Form





ExpIntegralEi[z] == ExpIntegralEi[x] + Pi I - I Pi Floor[(Pi + Arg[z])/(2 Pi)] + 2 I Pi Floor[Arg[z - x]/(2 Pi)] + Sum[((-1)^(k - 1)/(x^k k) + (x^(1 - k)/k!) HypergeometricPFQRegularized[ {1, 1}, {2, 2 - k}, x]) (z - x)^k, {k, 1, Infinity}] /; Element[x, Reals] && x < 0










Standard Form





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MathML Form







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Rule Form





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Date Added to functions.wolfram.com (modification date)





2007-05-02