Uniformly continuous function (sequence)

In summary, the conversation discusses a problem involving a positive continuous function and a sequence of functions defined by an integral. The main goal is to prove that the limit of this sequence is uniform on bounded intervals and to determine if it is also uniform on the entire real line. The individual's attempt at a solution involves fixing certain variables and evaluating the limit, but there is difficulty in accounting for the added variables. Help is requested.
  • #1
angst18
3
0

Homework Statement


(This is my first post and I'm not sure why the Tex code isn't working, sorry).Suppose [itex]f[/itex]is a positive continuous function on [itex][1,0] [/itex].For each natural number[itex]n[/itex] define a new function[itex]F_n [/itex] s.t.
[tex] F_n(x) = \int_0^1 t^ne^{xn}f(t)dt [/tex]

(a) Prove that [itex] lim_{n\to\infty}F_n(x) = 0 [/itex] for all real [itex] x [/itex].
(b) Prove that the above limit is uniform on each bounded interval [itex] [a,b] [/itex].
(c) Determine with proof or counterexample wether or not the limit is uniform on [itex] (-\infty, \infty) [/itex].

Homework Equations


The Attempt at a Solution



So, I know that what I'm supposed to do for part (a) is to show that the limit is uniform so that I can bring it into the integrand and evaluate. I even know how to do this in when there's only one variable, but the addition of a 't' as well as an 'x' has me stymied.
I know I'm supposed to fix [itex] f(t) [/itex]for [itex] t\in [0,1] [/itex] and [itex]x[/itex] (still not sure if i have to do the cases where [itex] x [/itex] is neg/pos) and then show that the limit is independent of [itex]x[/itex] and [itex]t[/itex], but there's something I'm not getting, or I'm doing it in the wrong order, because I'm basically totally stuck.
Thanks in advance for any help.
 
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  • #2
Hello angst18. Welcome to PF.

To get Tex to work:

After selecting "Preview Post", you need to click on your browser's "Refresh" button. Otherwise the display will not show the updated Tex image. Apparently some memory location doesn't get updated unless you do this.
 

FAQ: Uniformly continuous function (sequence)

What is a uniformly continuous function?

A uniformly continuous function is a type of function in mathematics that exhibits a specific type of behavior. Specifically, it means that the function's output values change smoothly or gradually as its input values change. This type of function is important because it allows for the analysis and understanding of many complex systems and phenomena.

How is a uniformly continuous function different from a regular continuous function?

A uniformly continuous function differs from a regular continuous function in that it exhibits a more strict type of continuity. While a regular continuous function may have small fluctuations or jumps in its output values, a uniformly continuous function has a smoother behavior and is continuous across the entirety of its domain.

Can you give an example of a uniformly continuous function?

Yes, a simple example of a uniformly continuous function is a linear function, such as f(x) = 2x. This function has a constant rate of change and its output values change smoothly as its input values change. Other examples include polynomial functions, exponential functions, and trigonometric functions.

How is a sequence related to a uniformly continuous function?

A sequence is a list of numbers that follows a specific pattern or rule. In the context of a uniformly continuous function, a sequence can be created by evaluating the function at a series of input values. The behavior of the sequence can then be analyzed to understand the behavior of the function as a whole.

Are there any real-world applications of uniformly continuous functions?

Yes, there are many real-world applications of uniformly continuous functions. They are commonly used in physics, engineering, and economics to model and understand the behavior of complex systems. For example, in physics, uniformly continuous functions can be used to describe the motion of objects, while in economics, they can be used to model the growth of a population over time.

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