Exact Solution for Integral of sin(x)/(10x+1) without Taylor Series?

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Homework Help Overview

The problem involves finding an exact result or a method for computing the exact result of the integral \(\int_0^5 \frac{\sin(x)}{10x-1} dx\). Participants are exploring alternatives to using Taylor series for this computation.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Some participants attempt to express the integral using a series expansion and consider a substitution to simplify the integral. Others raise questions about the nature of the integral, particularly regarding its behavior at \(x = 1/10\) and whether the principal value is relevant.

Discussion Status

The discussion is ongoing, with participants exploring different approaches and questioning the assumptions related to the integral's properties. There is recognition that the integral may not yield an elementary result.

Contextual Notes

Participants note the potential singularity at \(x = 1/10\) and discuss the implications of this on the evaluation of the integral.

eric222
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Homework Statement



The problem: finding an exact result (or at least a method for computing the exact result) of

\int_0^5 \frac{sin(x)}{10x-1} dx

Homework Equations



Is there any way to solve this integral other than using Taylor series?

The Attempt at a Solution



= \int_0^5 \sum_{i=0}^{\infty} \frac{(-1)^ix^{2i+1}}{(2i+1)!(10x+1)}dx
 
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eric222 said:

Homework Statement



The problem: finding an exact result (or at least a method for computing the exact result) of

\int_0^5 \frac{sin(x)}{10x-1} dx

Homework Equations



Is there any way to solve this integral other than using Taylor series?

The Attempt at a Solution



= \int_0^5 \sum_{i=0}^{\infty} \frac{(-1)^ix^{2i+1}}{(2i+1)!(10x+1)}dx

Hmm... let's try something...

\int_0^5 \frac{sin(x)}{10x-1} dx

u = x - 1/10

\int_{-.1}^{4.9} \frac{sin(u+.1)}{10u} dx

Whatever happens, though, it won't be an elementary integral, I'll tell you that right now. You can split the sin(u+.1) using the addition formula sin(x+y) = sin(x)cos(y) + cos(x)sin(y), but it won't be elementary.
 
Last edited:
Do you mean finding the principle value of this integral? What happens at x = 1/10...
 
quZz said:
Do you mean finding the principle value of this integral? What happens at x = 1/10...

How stupid of me. I should have noticed this directly.

Thanks for the help, everyone!
 

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