Prove/Disprove: Uniform Continuity of sin(sin(x))

In summary, the conversation discusses the challenge of proving or disproving the uniform continuity of the function sin(sin(x)) using the $\epsilon, \delta$ definition. The formula for sinx-siny is also mentioned, along with a clarification of the $\epsilon, \delta$ definition for a real function.
  • #1
solakis1
422
0
prove or disprove if the following function is uniformly continuous:

\(\displaystyle sin(sin(x)) \) using the ε,δ definition
 
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  • #2
Do you know what that means? What IS the "$\epsilon, \delta$ definition"?
 
  • #3
Country Boy said:
Do you know what that means? What IS the "$\epsilon, \delta$ definition"?
This is a challenge problem. solaklis wants you to find the answer...

-Dan
 
  • #4
hint
[sp]Use the formula :
sinx-siny =$2cos\frac{x+y}{2}sin\frac{x-y}{2}$[/sp]
 
  • #5
Country Boy said:
Do you know what that means? What IS the "$\epsilon, \delta$ definition"?
The $\epsilon$ $\delta$ definition for real function f(x) is :

Given $\epsilon>0$ there exists a $\delta>0$ such that :
For all x,y belonging the to domain of f(x) and $|x-y|<\delta$ then $|f(x)-f(y)|<\epsilon$
 

1. What is uniform continuity?

Uniform continuity is a property of a function that describes how smoothly it changes over its entire domain. A function is said to be uniformly continuous if, for any given value of epsilon, there exists a corresponding value of delta such that the distance between any two points on the graph of the function is less than epsilon whenever the distance between the corresponding points on the x-axis is less than delta.

2. Is sin(sin(x)) uniformly continuous?

Yes, sin(sin(x)) is uniformly continuous. This can be proven using the definition of uniform continuity and the fact that both sin(x) and sin(sin(x)) are continuous functions.

3. How do you prove uniform continuity?

To prove uniform continuity, we need to show that for any given value of epsilon, there exists a corresponding value of delta such that the distance between any two points on the graph of the function is less than epsilon whenever the distance between the corresponding points on the x-axis is less than delta. This can be done using the definition of uniform continuity and the properties of continuous functions.

4. Can you disprove uniform continuity?

Yes, it is possible to disprove uniform continuity by finding a counterexample where the definition of uniform continuity does not hold. This could happen if the function has a discontinuity or if the function is not defined for certain values of x.

5. Why is uniform continuity important?

Uniform continuity is important because it ensures that a function is well-behaved over its entire domain. This property is necessary for many mathematical and scientific applications, as it allows us to make accurate predictions and analyze the behavior of functions in a consistent and reliable way.

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