Is the Integral of 1/(x^2*lnx) Solvable Using Elementary Functions?

  • Thread starter Thread starter JustaNickname
  • Start date Start date
  • Tags Tags
    Integral
Click For Summary
SUMMARY

The integral ∫dx/(x^2*lnx) is not solvable using elementary functions, as confirmed by Maple 14, which returns a non-elementary function for this integral. The proposed integration by parts method using u = lnx and dv = dx/x^2 leads to an incorrect interpretation of the logarithmic term. The correct differentiation of the resulting expression should validate the solution, but the integral itself remains unsolvable in elementary terms.

PREREQUISITES
  • Understanding of integral calculus and integration techniques
  • Familiarity with integration by parts method
  • Knowledge of logarithmic functions and their properties
  • Experience with symbolic computation tools like Maple 14
NEXT STEPS
  • Research the properties of non-elementary integrals
  • Learn advanced integration techniques beyond elementary functions
  • Explore the capabilities of Maple 14 for symbolic integration
  • Study the implications of integrals that cannot be expressed in elementary terms
USEFUL FOR

Mathematicians, calculus students, and anyone interested in advanced integration techniques and the limitations of elementary functions in solving integrals.

JustaNickname
Messages
4
Reaction score
0
∫dx/(x^2*lnx)

What I`ve seen on the web but I don`t think is right:
u= lnx *** what we have here isn't lnx but (lnx)^-1... This is why I doubt that's the right solution
du = dx/x
dv = dx/x^2
v = -1/x

=-lnx/x + ∫dx/x^2
=-lnx/x - 1/x + C

Let me know if it is correct, thanks!
 
Physics news on Phys.org
I didn't check if it is correct myself, but you never really need someone to check if an integral (like this) is correct. Just differentiate it.
 
JustaNickname said:
∫dx/(x^2*lnx)

What I`ve seen on the web but I don`t think is right:
u= lnx *** what we have here isn't lnx but (lnx)^-1... This is why I doubt that's the right solution
du = dx/x
dv = dx/x^2
v = -1/x

=-lnx/x + ∫dx/x^2
=-lnx/x - 1/x + C

Let me know if it is correct, thanks!

Maple 14 gets a non-elementary function for this integral; that is, it cannot be done in terms of elementary functions of the type you have used.

RGV
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
Replies
5
Views
2K
  • · Replies 7 ·
Replies
7
Views
10K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
Replies
3
Views
2K
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K