How to integrate (ln x)(squared)

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Hi,

I've been struggling with this problem for hours, so I was wondering if someone here could help me out, thanks:

The problem is:

How to integrate: (ln x)(to the power of 2)

Thanks
 
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Curious6 said:
Hi,

I've been struggling with this problem for hours, so I was wondering if someone here could help me out, thanks:

The problem is:

How to integrate: (ln x)(to the power of 2)

Thanks
\int\left(\ln{x}\right)^{2}\,dx=x\left(\ln{x}\right)^{2}-2\int\ln{x}\,dx

\int\ln{x}\,dx=x\ln{x}-x

I just used part-integration:

\int v\,du=uv-\int u\,dv

...You should be able to put it together from here.
 
Ok, I understand now, thanks :biggrin: :-p
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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