Checking Mistake: Am I Wrong with $\ln\frac{1}{2}$?

  • Context: MHB 
  • Thread starter Thread starter jiasyuen
  • Start date Start date
  • Tags Tags
    Mistake
Click For Summary
SUMMARY

The integral $$\int_{0}^{1}\frac{1}{x-2}dx$$ evaluates to $$-\ln2$$, which is equivalent to $$\ln\frac{1}{2}$$. The confusion arises from the properties of logarithms, specifically that $$\ln(a) - \ln(b) = \ln\left(\frac{a}{b}\right)$$. The discussion clarifies that the initial calculation was correct, but the interpretation of the result needed adjustment to align with logarithmic identities.

PREREQUISITES
  • Understanding of integral calculus
  • Familiarity with logarithmic properties
  • Basic knowledge of limits and continuity
  • Experience with mathematical notation and expressions
NEXT STEPS
  • Review properties of logarithms, specifically $$\ln(a) - \ln(b)$$ and $$\ln(a^b)$$
  • Practice evaluating definite integrals involving logarithmic functions
  • Explore advanced integral calculus techniques, such as substitution and integration by parts
  • Study the implications of improper integrals and their convergence
USEFUL FOR

Students of calculus, mathematics educators, and anyone looking to deepen their understanding of logarithmic functions and integral evaluation.

jiasyuen
Messages
25
Reaction score
0
$$\int_{0}^{1}\frac{1}{x-2}dx$$

$$=\left [ \ln\left | x-2 \right | \right ]_{0}^{1}$$

$$=\ln1-\ln2$$

$$-\ln2$$

But the answer given is $$\ln\frac{1}{2}$$. Am I wrong?
 
Physics news on Phys.org
You're correct. Recall that $\ln(a)-\ln(b) = \ln \left(\frac{a}{b}\right)$ and $\ln(a^b) = b \ln(a)$.
 
I've forgotten that. Thanks for reminding.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
Replies
8
Views
4K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K