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Topic: Off Topic Physics/math question
Replies: 3   Last Post: Jan 5, 2013 12:35 PM

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dy/dx

Posts: 6
Registered: 11/10/12
Re: Off Topic Physics/math question
Posted: Jan 5, 2013 12:35 PM
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On Fri, 4 Jan 2013 20:59:09 -0800 (PST), wrschlanger@gmail.com wrote:

> ---
> If y(x) = 1 / x
> then y(x) > 0 when x > 0 and y(x) < 0 when x < 0.
>
> According to the power rule of Calculus, y'(x) = -1 / x^2.
> So y'(x) is always negative.
>
> Are we losing information by taking the derivative?


Yes, as evidenced by the constant of integration added going the other way.

> I think the place I make a mistake is in my understanding of how r relates to x.
> If everything is oriented along the x axis, aren't they the same? Or do we have
> r = |x| ?


The latter.



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