Ei( z )

The exponential integral Ei of z in SageMath. Alias of exp_integral_ei. Defined by

\[ \operatorname{Ei} (z) = \int_{-\infty}^z du \: \frac{ e^u }{ u } \]

Relation to exp_integral_e1 for x > 0 :

\[ \operatorname{Ei} (-x) = - E_1 (x) \]

Plot on the real axis:

Series expansion about root:

Special values:

Related functions:   exp_integral_ei   exp_integral_e1   exp_integral_e

Function category: exponential integrals sagemath-docs