Yucky Integral: Solving w/ Calculus

  • Thread starter Thread starter NutriGrainKiller
  • Start date Start date
  • Tags Tags
    Integral
Click For Summary

Homework Help Overview

The discussion revolves around evaluating a complex integral involving exponential functions and parameters, specifically focusing on the integral from negative to positive infinity. The subject area is calculus, particularly integral calculus.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts various methods such as distribution and substitution but finds them unsuccessful. Participants raise concerns about the integrand's behavior at specific points and question the nature of the parameters involved.

Discussion Status

Participants are exploring different interpretations of the parameters in the integral, with some suggesting that they may be constants rather than variables. There is also mention of using computational tools for integration, though concerns about their limitations are noted.

Contextual Notes

There are discussions about the assumptions regarding the parameters \lambda, \mu_1, and \mu_2, as well as the challenges posed by the integrand's singularities at certain values of x.

NutriGrainKiller
Messages
60
Reaction score
0
The following has been extracted from a larger assignment, the details of which I do not believe are necessary. Anywho, here it is:

[tex]\frac{1}{\pi}\int\frac{1}{x(\lambda-x)} e^{-(\frac{x-\mu_1}{\lambda-x})^2} e^{-(\frac{x-\mu_2}{x})^2} dx<br /> [/tex]

things to keep in mind: [tex]\lambda[/tex] as well as [tex]\mu_1[/tex] and [tex]\mu_2[/tex]is only a variable, and the integral ranges from -infiniti to +infiniti.

What I've tried: distributing out, trying to combine/reduce exponentials (unsuccessful), tried u/du substitution - this seems like it would work, but i couldn't get it to.

I have completed four semesters of undergraduate calculus, so this isn't new however I'm not quite sure how to go about reducing this. Any tips would be greatly appreciated.
 
Last edited:
Physics news on Phys.org
The integrand has problems at x=0 and x=\lambda. How would you normally deal with such problems ?
 
A lazy physicist writes:

Anybody who isn't a mathematician would use Mathematica's the 'Integrator' to solve integrals of this type. (Google 'The Integrator')

It's important to know how to solve a certain number of integrals by rote and experience. However, I don't see the point of torturing yourself over such complicated integrals as the above- unless they represent some physically interesting phenomenon.
 
I assume you mean that [itex]\lambda[/itex] as well as [itex]\mu_1[/itex] and [itex]\mu_2[/itex] are NOT variables but are constants.
 
christianjb, the integrator doesn't understand the different symbols, like the [itex]\lambda[/itex], it can only integrate things that only have x's in it. No way to tell it that those others are constants.

So either fork out some cash and buy mathematica, or start crying.

EDIT: No it seems i was wrong, they obviously changed it >.< Well yea your going to have to change the greek letters into ones on your keyboard and convert back.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
Replies
6
Views
3K
Replies
7
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
Replies
20
Views
2K
  • · Replies 27 ·
Replies
27
Views
4K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 9 ·
Replies
9
Views
4K