Integrating a logarithmic function

Click For Summary

Discussion Overview

The discussion revolves around the integration of the logarithmic function log base a of x. Participants explore the existence of a formula for this integral, comparing it to the more commonly referenced integral of ln x. The conversation includes considerations of substitution methods and the implications of changing the base of the logarithm.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant expresses confusion about the absence of a specific integral formula for log base a of x, questioning whether it exists or if it is particularly complex.
  • Another participant provides a relationship between log base a of x and natural logarithm, suggesting a method to convert the base for integration.
  • A participant inquires about the appropriate method for integrating the function after applying the change of base, considering substitution as a potential approach.
  • It is noted that ln(a) is a constant and can be factored out during integration.
  • A later reply reflects a realization about the integration process, indicating a moment of clarity regarding the discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the integration process, as there are multiple approaches suggested and some uncertainty remains regarding the best method to apply.

Contextual Notes

The discussion does not resolve the complexities involved in integrating log base a of x, and assumptions about the methods of integration are not fully explored.

Math Is Hard
Staff Emeritus
Science Advisor
Gold Member
Messages
4,663
Reaction score
36
I noticed than in the chapters I am studying now that while they give us a formula for taking the derivative of log base a of x, I can't find a correspoding formula for finding the integral of log base a of x.
We have a table of integrals in the back of the book, but I only see integrals pertaining to forms of ln x.
So.. am I missing something? Does it not exist? Is it something so ugly I don't even want to know about it??

Thanks!
 
Physics news on Phys.org
[tex]\log_a{x} = \frac{\ln{x}}{\ln{a}}[/tex]

cookiemonster
 
ok, so I use change of base to convert. Then to integrate, do I use substitution, or is it simpler than that? thanks.
 
ln(a) is a constant. It comes right out front.

cookiemonster
 
Oh crud! I walked away from the computer after my last post and then all of a sudden it hit me like a ton of bricks! :eek:
thanks, CM. You are going to be a big hit at CalTech. :biggrin:
 

Similar threads

  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 21 ·
Replies
21
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K