Determining what values a function converges at

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In summary, the conversation discusses finding the values of p and q for which the integral dx / (x^p * (ln(x))^q) from 1 to infinity converges. The approach is to compare the growth behavior of the function to simpler functions and determine critical values of p and q.
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Homework Statement


For what values of p and q does the integral

dx / (x^p * (ln(x))^q) from 1 to infinity
WN86r.gif


converge?

Homework Equations


integration


The Attempt at a Solution


I have no idea how to start figuring this out. I've tried trig substitutions but can't find something that actually makes progress.
 
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  • #2
You don't need to actually evaluate the integral of (find a primitive of) [tex]x^{-p} \log^{-q} x[/tex] for generic [tex]p[/tex] and [tex]q[/tex]. Instead, compare the growth behavior of this function to simpler functions whose integrals you know converge or diverge, and try to find critical values of [tex]p[/tex] and [tex]q[/tex] where the behavior changes.
 

FAQ: Determining what values a function converges at

What is the definition of convergence in terms of a function?

Convergence of a function refers to the behavior of the values of the function as the input approaches a specific value or goes towards infinity. It describes whether the function approaches a certain value or diverges as the input gets closer to a particular value.

How do you determine the values at which a function converges?

To determine the values at which a function converges, we need to analyze the behavior of the function as the input approaches a specific value or goes towards infinity. This can be done by evaluating the limit of the function as the input approaches the given value or infinity.

What is the difference between pointwise and uniform convergence of a function?

Pointwise convergence of a function means that for each input, the values of the function approach a specific value. On the other hand, uniform convergence means that the values of the function approach a specific value at the same rate for all inputs.

How do you prove that a function converges at a certain value?

To prove that a function converges at a certain value, we need to show that the limit of the function as the input approaches the given value exists and is equal to the value itself. This can be done by using the definition of limits and evaluating the limit of the function.

Are there any special cases where a function may not converge at a certain value?

Yes, there are certain cases where a function may not converge at a certain value. This can happen when the limit of the function does not exist or when the function oscillates between different values as the input approaches the given value. In these cases, the function is said to diverge.

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