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February 16th, 2011, 10:07 PM   #1
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The length of a curve with logaritm (Natural)

Hi guys the problem is to get the length of the curve

y= ln(x^2-1) 0<= x <= 1/2
As far as I am concerned we can use a formula

L = $(from a to b) SQRT [1+ f'(x)] dx

I don't know how to get the derivative of the function,

could someone help me complete this task
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February 16th, 2011, 10:37 PM   #2
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Re: The length of a curve with logaritm (Natural)

In your formula, you need to square f'(x) in the radicand of the integrand.

While the integral will return a real value, is it meaningful? The curve is not defined on [-1,1], although W|A shows it has a real and imaginary part on this interval.

It looks like the same result would be returned by using which is defined on (-1,1).

Also confusing to me is that W|A shows the same graph for both functions.
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