Commute of Limits and Integrals: Understanding the Relationship

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SUMMARY

The discussion centers on the commutation of limits and integrals, specifically questioning whether limits commute in the context of functions. The user concludes that limits do not commute, as demonstrated through testing various functions. Additionally, it is clarified that integrals and limits do not always commute, emphasizing the importance of understanding the role of free variables in expressions involving limits.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with integrals and their properties
  • Knowledge of free variables in mathematical expressions
  • Basic proof techniques in mathematical analysis
NEXT STEPS
  • Study the properties of limits and their behavior with respect to free variables
  • Explore the conditions under which integrals and limits commute
  • Learn about theorems related to the interchange of limits and integrals
  • Investigate specific examples of functions where limits do not commute
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Mathematics students, educators, and anyone involved in advanced calculus or mathematical analysis who seeks to deepen their understanding of limits and integrals.

moo5003
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I was wondering if Limits commute,

Ie:
Limit of z to infinity[ Limit of z to 0[ f(0)/z ]]

=

Limit of z to 0[ Limit of z to infinity[ f(0)/z ]]

Edit: Nvm, they dont... I just did a some test functions... I'm just hoping for an easy way to finish one of my proofs.

Though on a sidenote, integrals and limits do commute right?
 
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This doesn't even make sense. The only way "Limit of z to A[Expression]" even makes sense is if z is a free variable in the Expression. But in both "Limit of z to 0[ f(0)/z ]" and "Limit of z to infinity[ f(0)/z ]", z is NOT a free variable. Note that in "f(0)/z", z is a free variable, but in "Limit of z to B[ f(0)/z ]", it is not. (In the above, A and B can of course be anything, not just 0 and infinity which you've used in your examples). So I don't see how you could have determined:

Edit: Nvm, they dont... I just did a some test functions...

since it doesn't even make sense.

And integrals and limits don't always commute.
 
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