Anti derivative of the function x/lnx

  • Thread starter Thread starter Murad A.Omar
  • Start date Start date
AI Thread Summary
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
 
Mathematics news on Phys.org
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.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Thread 'Imaginary Pythagorus'
I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
Back
Top