The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math.num-analysis

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Removing singularity at x=0 for integral
Replies: 7   Last Post: Nov 28, 2013 3:25 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 17
Registered: 8/7/07
Removing singularity at x=0 for integral
Posted: Nov 26, 2013 10:10 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hi I'm trying to numerically integrate the following expression from 0 .. 1
f(x)=1/x^1.5 * exp(-A/x) , where A is a constant.

As x->0, the exponential goes to zero faster than the power, so f(x)->0, as x-> 0.
I'm evaluating this integral at various values of A - there are cases when A is very small.

I'm trying to find a way to remove the singularity at x=0. I've looked at the usual techniques, like integration by parts, subtracting the singularity out, change of variables.

The change of variables is usually done when the power is less than one e.g.(1/sqrt(x)). exp(-A/x) is not analytic so integration by parts seems problematic.

Any suggestions?

Thanks for any assistance.

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.