Help Improper Integrals Type 2 argg

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Homework Help Overview

The discussion revolves around evaluating an improper integral involving absolute values and square roots, specifically the integral from 1 to 3 of the function 1/(sqrt[abs(x-2)]) dx. Participants are exploring the challenges associated with the absolute value and the behavior of the function near the point where the expression inside the absolute value changes sign.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the necessity of splitting the integral at the point where the absolute value changes, specifically at x=2. There are attempts to evaluate the integral by considering limits and different cases for the absolute value. Some participants express confusion about the results they are obtaining, particularly regarding the limits and the final value of the integral.

Discussion Status

The conversation is ongoing, with participants sharing their attempts and questioning the methods being used. Some guidance has been offered regarding the splitting of the integral, but there is no clear consensus on the correct approach or final answer as participants continue to explore different interpretations and calculations.

Contextual Notes

There is mention of limits approaching the point of discontinuity at x=2, which raises questions about how to handle the integral correctly in that region. Additionally, there is a reference to a discrepancy between participants' results and the expected answer from a textbook.

cmab
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I don't understand my Math Homework, here's the number that I don't get.

[int a=1 b=3] 1/(sqrt[abs(x-2)]) dx

sqrt = square root
abs = absolute value
Integral from 1 to 3

Can anyone explain this to me clearly, I'll really appreciate :smile:

Thanks
 
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I tried and it keeps giving me 0.

2[sqrt(abs(x-2))] from 1 to t and 2[sqrt(x-2)] from t to 3

(2[sqrt(abs(1-2))])-(2[sqrt(abs(t-2))])
and
(2[sqrt(abs(t-2))])-(2[sqrt(abs(3-2))])

(lim t->2+ (2[sqrt(abs(t-2))])-(2[sqrt(abs(1-2))]) )
+
(lim t->2- (2[sqrt(abs(3-2))])-(2[sqrt(abs(t-2))]) )
=4

in the book it says 3/4
 
Last edited:
Try and remember whenever you have a problem dealing with absolute values, think, "split in two". That is, split it into two parts: one part is when the value between absolute values is positive, and another part when the value is negative. So:

[tex]|x-2|=x-2 \quad\text{ when }\quad x-2\geq 0[/tex]

[tex]|x-2|=-(x-2) \quad\text{ when }\quad x-2<0[/tex]

so, split the integral into two, you know, at 2, and then solve it. Remember to replace the absolute value expression in the radical with the appropriate form (from above) for each interval. Can you do this?
 
saltydog said:
Try and remember whenever you have a problem dealing with absolute values, think, "split in two". That is, split it into two parts: one part is when the value between absolute values is positive, and another part when the value is negative. So:

[tex]|x-2|=x-2 \quad\text{ when }\quad x-2\geq 0[/tex]

[tex]|x-2|=-(x-2) \quad\text{ when }\quad x-2<0[/tex]

so, split the integral into two, you know, at 2, and then solve it. Remember to replace the absolute value expression in the radical with the appropriate form (from above) for each interval. Can you do this?

Nice, i check it out on gragphmatica, and the graph of both seems to match the original function. Thanks dude, if i have a question i<ll comme back here :-p
 
But the limit for that problem have to approch 2 from the right for the x-2, and from the left for -(x-2). Right ?
 
No limit considerations are involved. Just solve two integrals. I'll set up one for you:

[tex]\int_1^2 \frac{dx}{\sqrt{2-x}}[/tex]

What's the other one?
 
I did the thing, and it still gives me 4 :cry:
 

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