Struggling with an Integral Involving Natural Logarithms?

In summary, the conversation discusses the difficulty of solving a specific integral and provides hints and strategies for finding the solution. The integral in question is (sqrt(1+ln(x)))/xln(x) dx and it is suggested to substitute ln(x) with u in order to solve it.
  • #1
kennis2
8
0
(edited need help) hard integral to me but you?

I tried much but i couldn't resolve.. :grumpy:
Integral of (1+ln(x))/xln(x) dx
thanks =)
 
Last edited:
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  • #2
Hint:
What is
[tex]\frac{d}{dx}(xlnx)=?[/tex]
 
  • #3
its 1/x right?
 
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  • #4
No, you must use the product rule:
[tex]\frac{d}{dx}(xln(x))=1*ln(x)+x*\frac{1}{x}=ln(x)+1[/tex]
What does that tell you?
 
  • #5
oh you are right!
I know the answer then, BUT
I WROTE MY EXERCISE BAD SORRY HERE GO AGAIN
integral of (sqrt(1+ln(x)))/xln(x) dx
 
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  • #6
Does this pertain to finding the arc length of a function? Also, try writing it out in latex, you'll probably get more responses.
 
  • #7
is this the question??

[tex] \frac{\sqrt{1+\ln x}}{x \ln x} dx [/tex]?

in which case substitute ln x = u and solve away!
 

1. What is a "hard integral"?

A hard integral is a mathematical concept that involves finding the area under a curve or the volume of a three-dimensional shape. It is considered "hard" because it often requires advanced mathematical techniques and can be challenging to solve.

2. Why is the "hard integral" important?

The hard integral is important because it has many real-world applications, such as in physics, engineering, and economics. It allows us to calculate quantities such as displacement, work, and profit, which are crucial in understanding and predicting the behavior of systems.

3. What makes the "hard integral" difficult to solve?

The difficulty of solving a hard integral depends on various factors, such as the complexity of the integrand (the function inside the integral), the limits of integration, and the techniques required to solve it. In some cases, the hard integral may not have a closed-form solution, and numerical methods must be used.

4. How do you approach solving a "hard integral"?

When faced with a hard integral, it is essential to first identify the type of integral and the techniques that can be used to solve it. These techniques may include substitution, integration by parts, trigonometric identities, and partial fractions. It is also crucial to carefully manipulate the integrand and use algebraic techniques to simplify the integral before attempting to solve it.

5. Are there any tips for effectively solving a "hard integral"?

Some tips for solving a hard integral include practicing regularly, understanding the fundamentals of integration, and being familiar with various techniques. It is also helpful to start by simplifying the integrand and breaking down the integral into smaller, more manageable parts. Additionally, using a graphing calculator or online integral solver can help check your work and provide insight into the solution.

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