Integrate dx/(xlogx): Limits 1 to n - Result

In summary, the integration of dx/(xlogx) within the limits 1 and n does not converge. This can be seen by making the substitution u=ln x and evaluating ln u at 0, which results in the integral not converging. The function 1/(xlogx) also goes to infinity at x=1, indicating that the area under the curve is infinite.
  • #1
prasoonsaurav
2
0
Is there any way to integrate
[tex]\int dx/(xlogx)[/tex]

within the limits 1 and n?

If yes what is the result?
 
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  • #2
Assuming that log x means ln x (if not a constant is just introduced), if you make the substitution u= ln x the integrand simplifies to du/u. However the limits are 0 to ln n, and so ln u would have to be evaluated at 0, which means the integral does not converge.
 
  • #3
Yes the integral doesn not converge . This can be seen without integrating - the function 1 / (x * ln x) goes to infinity at x = 1 , and also func is continuous in the interval .. so the area under the curve is infinite
 

Related to Integrate dx/(xlogx): Limits 1 to n - Result

1. What is the result of integrating dx/(xlogx) from 1 to n?

The result is ln(ln(n)).

2. How do you solve this integral?

This integral can be solved using integration by parts, where u = logx and dv = dx/x. After applying the formula, the integral becomes ln(x)ln(lnx) - ∫ ln(lnx)/x dx. This can then be solved using substitution.

3. Why is the lower limit 1 in this integral?

The lower limit of 1 is used because the integral is undefined for x = 0. Therefore, we must start at the smallest possible value, which is 1.

4. Can this integral be solved using any other methods?

Yes, this integral can also be solved using the substitution method by letting u = logx. The integral then becomes ∫ du/u, which can be solved using the natural log function.

5. Are there any applications of this integral in science?

Yes, this integral often appears in the field of statistics, specifically in the calculation of entropy and information theory. It is also used in the study of logarithmic functions and their properties.

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