How to integrate x^(-a)*e^(-b/x), where a, b are constants?

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SUMMARY

The integration of the function x^(-a) * e^(-b/x), where a and b are constants, can be approached using various methods. Users in the discussion noted that tools like Wolfram Alpha and Maple provide solutions, with Maple yielding results in terms of exponentials and Whittaker M functions. The substitution u = b/x is suggested for simplifying the integral. The discussion also touches on the Gamma function and its relevance to the problem, particularly in the context of posterior distributions.

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wow, you are really good.

Yes, I wrote a simplified version of inverse-gamma. I am looking for the posterior distribution.
 
colstat said:
wow, you are really good.

Yes, I wrote a simplified version of inverse-gamma. I am looking for the posterior distribution.

Try the substitution u = b/x

I am assuming you have 0 to infinite has bounds of the integral
 
colstat said:

Homework Statement


How do you integrate this?
x-ae-b/x, where a and b are some constants.


The Attempt at a Solution


I have tried this
http://integrals.wolfram.com/index.jsp?expr=x+*+e^%28-1%2Fx%29&random=false


Is there a closed form of this?

Maple gets an answer in terms of exponentials and Whittaker M functions. Of course, you might not regard that as a "closed form", since Whittaker functions are not "elementary".

RGV
 

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