Anti derivative of the function x/lnx

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The discussion centers on finding the antiderivative of the function x/ln(x). It is noted that there is no closed-form solution for this integral using elementary functions. However, a closed expression involving the exponential integral function, denoted as Ei, is provided: the antiderivative can be expressed as -Ei(1, 2ln(x)). The use of the Ei function is highlighted as significant, contributing to deeper insights in mathematical theory, despite the lack of a primitive function for the integral.
Murad A.Omar
hi
how are you all
can you help me in finding the anti derivative of the function
x/lnx
 
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As-salaam alaikum!

There's no closed-form solution for that integral, unfortunately.
 
Although no elementary functions can be found, a closed expression is

[inte]x/Ln(x)dx= -Ei(1,2Ln(x)),

so that you can approximate the values of the function.

P.S: It is not infortunate (for me) that there is no primitive, since the Ei function is an essential ingredient of the theory and has led to marvellous new insights.
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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