Difference between revisions of "Ei(x)=-Integral from -x to infinity of e^(-t)/t dt"
From specialfunctionswiki
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==Theorem== | ==Theorem== | ||
The following formula holds: | The following formula holds: | ||
− | $$\mathrm{Ei}(-x) = -\displaystyle\ | + | $$\mathrm{Ei}(-x) = -\displaystyle\int_{-x}^{\infty} \dfrac{e^{-t}}{t} \mathrm{d}t,$$ |
where $\mathrm{Ei}$ denotes the [[exponential integral Ei]] and $e^{-t}$ denotes the [[exponential]]. | where $\mathrm{Ei}$ denotes the [[exponential integral Ei]] and $e^{-t}$ denotes the [[exponential]]. | ||
Revision as of 00:41, 24 March 2018
Theorem
The following formula holds: $$\mathrm{Ei}(-x) = -\displaystyle\int_{-x}^{\infty} \dfrac{e^{-t}}{t} \mathrm{d}t,$$ where $\mathrm{Ei}$ denotes the exponential integral Ei and $e^{-t}$ denotes the exponential.