Definition:Exponential Integral Function/Formulation 1

Definition

The exponential integral function is the real function $E_1: \R_{>0} \to \R$ defined as:

$\map {E_1} x = \ds \int_{t \mathop = x}^{t \mathop \to +\infty} \frac {e^{-t} } t \rd t$

Also see

• Results about the exponential integral function can be found here.

Sources

• 1965: Murray R. Spiegel: Theory and Problems of Laplace Transforms ... (previous) ... (next): Chapter $1$: The Laplace Transform: Some Special Functions: $\text {VI}$. The Exponential integral