(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Calcualte the value of [tex]\int\limits_L \sqrt{x^2+y^2}dl[/tex], where L is an arc of a logarithmic spiral [tex]r=ae^{m\phi}[/tex] between points A(0,a) and B([tex]-\infty[/tex],0).

Problem: I can't find a value of [tex]\phi[/tex] where x=[tex]-\infty[/tex] or y=a.

2. Relevant equations

We parametrise and get:

[tex]x=ae^{m\phi}\cos(\phi)[/tex]

[tex]y=ae^{m\phi}\sin(\phi)[/tex]

3. The attempt at a solution

Well, I guess I can't do much without the boundaries. I typed the equation for y=a into mathematica and got error messages, more or less the same for function Solve and Reduce (that the equation can not be solved using algebraic methods).

Obviously, the equation x=[tex]-\infty[/tex] doesn't give any result either. Help, please!

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# Homework Help: Line integral & logarithmic spiral

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