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I have found that

$$\int\limits_0^1 {\dfrac{{x - 1}}{{\ln x}}} \;\text{d}x=\ln2$$

but I can't prove it. Any hint?

Thank you in advance

Milind Hegde
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Raffaele
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1 Answers1

8

$$t>-1:$$

$$\begin{aligned}f(t)=\int_0^1 \frac{x^t-1}{\ln x}\,dx\;\Rightarrow\; f'(t) &=\int_0^1 x^t\,dx =\frac{1}{t+1}\end{aligned}$$

$$f(1)=\int_0^1 \frac{dt}{t+1}=\ln 2$$

L. F.
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