Integrability of Sinusoidal Function on [-1, 1]: Finding L(f, P) and U(f, P)

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SUMMARY

The function f(x) = sin(1/x²) for x in [-1, 0) ∪ (0, 1] and a at x = 0 is integrable on the interval [-1, 1]. To find the lower sum L(f, P) and upper sum U(f, P), one can utilize theorems related to Riemann integrability, particularly focusing on the behavior of the function outside the interval [-ε, ε]. It is essential to choose partitions that approach 0 as ε approaches 0 to accurately evaluate the integrability despite the oscillatory nature of the function.

PREREQUISITES
  • Understanding of Riemann integrability
  • Familiarity with the properties of oscillatory functions
  • Knowledge of partitioning methods in calculus
  • Basic concepts of limits and epsilon-delta definitions
NEXT STEPS
  • Study theorems on Riemann integrability and their applications
  • Learn about partitioning techniques for oscillatory functions
  • Explore the concept of limits in the context of integrability
  • Investigate the implications of choosing ε in Riemann sums
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Students studying calculus, particularly those focusing on Riemann integrability, and educators seeking to enhance their understanding of oscillatory functions in integration.

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The problem states:

Decide if the following function is integrable on [-1, 1]

f(x)=\left\{{sin(\frac1{x^2})\;\text{if}\;x\in[-1,\;0)\cup(0,\;1]\atop a\;\text{if}\;x=0}

where a is the grade, from 1 to 10, you want to give the lecturer in this course

What I don't understand is how to find L(f, P) and U(f, P) since when I look at the graph of the function it oscillates a lot. So how do I choose the partition. It seems I would need an infinite partition almost to make it work. Or is there another way to do it?

Any help would be much appreciated as I am really lost on this problem.'

Edit: Sorry for the function not showing properly, don't know what I did wrong there

Should be

sin(\frac1{x^2})\;\text{if}\;x\in[-1,\;0)\cup(0,\;1]
&
a\;\text{if}\;x=0
 
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Showing something is Riemann integrable doesn't mean you have to choose partitions. You probably have some theorems that you can use to show f(x) is Riemann integrable outside of any interval [-\epsilon,\epsilon]. Now show you can choose upper and lower partitions inside that interval that approach 0 as ε approaches 0.
 

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