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I have an equation of the the form $$-\Phi=(\frac{1}\gamma)^2\frac{d} {d\gamma}(\gamma^2 d\Phi/d\gamma) $$ to solve for $\Phi$. It can apparently be solved in two ways; one of which being to substitute $\Phi=f(\gamma)/\gamma$ and find the differential for $f(\gamma)$. The result should come out in terms of sin or cos, but I honestly don't know how.

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    Can you include in the question what you get when you substitute $\Phi=f(\gamma)/\gamma$?2012-04-12
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    either $\Phi=A \frac{\sin\gamma}\gamma$ or $\Phi=B \frac{\cos\gamma}\gamma$2012-04-12
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    Then what's the problem?2012-04-12
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    Sorry; that's the result I expect to find, I just don't know how to get there. As far as I can tell, I get as far as $f''/\gamma -f'/\gamma^2 - f/\gamma=0$. Then on I'm stuck.2012-04-12
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    You've made a mistake in your derivation; you shouldn't get the $f'/\gamma^2$ term, and the $f/\gamma$ term shouldn't have a negative sign. If you had included your derivation in the question like I had said in the first place, we could tell you where you went wrong.2012-04-12

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