# Exponential integral En(x) Calculator

## Calculates the exponential integral En(x).

 $E_n(x)={\large\int_{\small 1}^{\hspace{25}\small\infty}\frac{\large e^{-xt}}{\large t^n}}dt$

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 $\normal Exponential\ integral\ E_n(x)\\[10](1)\ E_n(x)={\large\int_{\small 1}^{\hspace{25}\small\infty}\frac{\large e^{-xt}}{\large t^n}}dt\\(2)\ E_n(0)={\large\frac{1}{n-1}}\\[10](3)\ E_1(x)=-E_i(-x)\\$

Exponential integral En(x)
 [1-6] /6 Disp-Num5103050100200
[1]  2014/12/19 04:30   Male / 60 years old level or over / High-school/ University/ Grad student / Very /
Purpose of use
at home without handbook tables
Comment/Request
very useful for this purpose
[2]  2012/01/08 06:28   Male / 40 years old level / Others / Very /
Purpose of use
I am a rewtired Physical Chemistry Professor and am using Physical Chemistry to do calculation of greenhouse gas fluxes. I need values of the exponential integral function to evaluate the fluxes.
Comment/Request
I am just startying, but what you are providing will be of great use to me.
[3]  2010/05/14 18:50   Female / 50 level / A researcher / Very /
Purpose of use
Exponential Integral function has no short-term expansion for values around 1 or .75. This was useful for that.
Comment/Request
Great!!!
[4]  2009/12/23 15:50   Female / 20 level / A specialized student / Very /
Purpose of use
project
Comment/Request
this site helped me a lot for my project purpose...thanks a lot.....
[5]  2009/10/02 08:19   Male / 30 level / A university student / Very /
Purpose of use
Special functions calc
Comment/Request
It's a great tool!
[6]  2009/05/01 18:03   - / 50 level / A teacher / Very /
Purpose of use
Dose assessment
Comment/Request
Thanks!

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