- #1
Discovering A^2: Attachment with Question and Solution Included
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Homework Help Overview
The discussion revolves around a problem involving the integration of a function related to quantum mechanics, specifically focusing on determining the value of a constant A when the function equals zero. The original poster has provided an attachment with their question and attempted solution.
Discussion Character
- Exploratory, Assumption checking, Problem interpretation
Approaches and Questions Raised
- Participants are examining the integration of the function A (sin(2pi/L) x) and questioning the correctness of the integral setup. Some participants express confusion over the attachment's readability and suggest that the original poster clarify their question and solution in text form. There are also discussions about the final answer and the steps leading to it, with emphasis on evaluating the integral correctly.
Discussion Status
Several participants have provided feedback on the clarity of the original poster's attachment and have raised questions about the integration process. There is an ongoing exploration of the assumptions made in the problem setup, and some guidance has been offered regarding the evaluation of the integral and the interpretation of the function.
Contextual Notes
Participants have noted the challenges posed by the unreadable attachment and have emphasized the importance of adhering to forum standards for clarity. There is also a mention of the need for a foundational understanding of calculus in relation to the problem being discussed.
- #2
HallsofIvy
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I have great difficulty reading this but it appears that you are integrating the function A (sin(2pi/L) x from 0 to L. That a rather trivial integral. Are you sure it isn't A sin((2pi/L) x)= A sin(2pi x/L)?
You also have "x" in your final answer. Since this is a definite integral, evaluated for x equal to the limits of integration, there should be no "x" in the result.
You also have "x" in your final answer. Since this is a definite integral, evaluated for x equal to the limits of integration, there should be no "x" in the result.
- #3
Pruddy
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Thank you so much hallsoflvy for your reply. I am very grateful! I have attached a new picture to this email. I am looking for the value of A when the function is equal to zero. The final answer is sqrt (2/L). I want to understand the steps and how they got the final answer. Thanks so much in advance!
Attachments
- #4
Ray Vickson
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Pruddy said:
Your attachment is essentially unreadable. Why not adhere to PF standards and just type out the problem and your proposed solution?
- #5
Kidiz
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Ray Vickson said:
Doing this would also help future readers, in case your picture gets deleted or something.
- #6
- #7
Kidiz
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Pruddy said:
The ##X## is most likely an argument of the function ##\sin##, that is, it should be inside the brackets. Why are you studying quantum mechanics without doing calculus first? You should definitely study calculus before. This is the simplest math you'll encounter.
But answering your question:
https://en.wikipedia.org/wiki/Fundamental_theorem_of_calculus#Corollary
- #8
HallsofIvy
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Once again, you have not completed the integral- evaluate it at the two limits of integration and subtract. After that it should be easy to solve the equation for A.
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