Why Is the Integral of 1/(4-ln(x)) Challenging?

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Homework Statement



Find the integral, I , of the followin' function.

Homework Equations



\int \frac{dx}{4 - lnx}.

3.Attempt

U = sqrt(lnx)
dx = 2xlnx du

Therefore

\int \frac{2xlnxdu}{4 - U^2}.

Integration of this f(x) failed

These are all integrals we have dealt with

http://www.mathwords.com/i/integral_table.htm
 
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KillaKem said:
Find the integral, I , of the followin' function.

Homework Equations



\int \frac{dx}{4 - lnx}.

There is no closed-form solution in terms of elementary functions, but if you use the substitution u=4-\ln(x), you can express the integral in terms of the special function called exponential integral function.
 
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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