Limit question (from complex analysis)

Click For Summary
SUMMARY

The discussion focuses on proving that the limit as h approaches 0 of the expression (1/h) * integral[f(z) - f(w)] dz equals 0, where f is a continuous function and the integral is taken over a contour. The key insight is that the continuity of f ensures that for any ε > 0, there exists a δ > 0 such that if z is within δ of w, then f(z) is within ε of f(w). The participant suggests using the ML Estimate to resolve the indeterminate form arising from the (1/h) term approaching infinity while the integral approaches 0.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with continuous functions
  • Knowledge of contour integration
  • Proficiency in applying the ML Estimate in analysis
NEXT STEPS
  • Study the properties of continuous functions in calculus
  • Learn about contour integration techniques
  • Research the ML Estimate and its applications in complex analysis
  • Explore examples of limits involving integrals and their evaluations
USEFUL FOR

Students and professionals in mathematics, particularly those studying calculus and complex analysis, will benefit from this discussion. It is especially relevant for those looking to deepen their understanding of limits and integration techniques.

synapsis
Messages
9
Reaction score
0

Homework Statement



This seems to be just a simple limit problem and I feel like I should know it but I'm just not seeing it.

I have a continuous function f, and a fixed w

I want to show that the limit (as h goes to 0) of the absolute value of:

(1/h)*integral[ f(z)-f(w) ]dz = 0 (the integral is over a contour)


Homework Equations



I believe the key to the problem is that f is continuous.

The Attempt at a Solution



For any a>0 there exists a b>0 such that z within b of w implies f(z) within a of f(w).

The problem is it seems to me like the 1/h term is going to infinity while the integral term is going to 0, which is indeterminate so I don't know how to get that the limit goes to 0.
 
Physics news on Phys.org
Oh, I have an idea. The contour I'm integrating over is the line connecting w+h to w. So I believe I can use the ML Estimate to show the limit goes to 0...
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
8
Views
3K
  • · Replies 21 ·
Replies
21
Views
1K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 20 ·
Replies
20
Views
2K
Replies
7
Views
2K