How to integrate (ln x)(squared)

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In summary, the conversation is about a person struggling with a problem involving integration of (ln x)^2 and asking for help. The solution involves using part-integration and simplification.
  • #1
Curious6
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Hi,

I've been struggling with this problem for hours, so I was wondering if someone here could help me out, thanks:

The problem is:

How to integrate: (ln x)(to the power of 2)

Thanks
 
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  • #2
Curious6 said:
Hi,

I've been struggling with this problem for hours, so I was wondering if someone here could help me out, thanks:

The problem is:

How to integrate: (ln x)(to the power of 2)

Thanks
[tex]\int\left(\ln{x}\right)^{2}\,dx=x\left(\ln{x}\right)^{2}-2\int\ln{x}\,dx[/tex]

[tex]\int\ln{x}\,dx=x\ln{x}-x[/tex]

I just used part-integration:

[tex]\int v\,du=uv-\int u\,dv[/tex]

...You should be able to put it together from here.
 
  • #3
Ok, I understand now, thanks :biggrin: :-p
 

FAQ: How to integrate (ln x)(squared)

What is the basic method for integrating (ln x)²?

The basic method for integrating (ln x)² is to use the substitution rule. Let u = ln x, then du = 1/x dx. Substitute these values into the integral and rewrite it in terms of u. This will result in an integral that can be easily solved using basic integration rules.

Can the power rule be used to integrate (ln x)²?

No, the power rule cannot be used to integrate (ln x)² directly. This is because the power rule only applies to functions with a constant exponent, while (ln x)² has a variable exponent.

Is there a shortcut for integrating (ln x)²?

Yes, there is a shortcut for integrating (ln x)² using the formula ∫(ln x)² dx = x(ln x)² - 2xln x + 2x + C. This formula can be derived using integration by parts.

Can the natural logarithm be simplified before integrating (ln x)²?

No, the natural logarithm cannot be simplified before integrating (ln x)². In fact, it is important to keep it in its original form to properly solve the integral.

Are there any real-life applications of integrating (ln x)²?

Yes, integrating (ln x)² can be used in various fields such as physics, engineering, and economics. For example, it can be used to determine the area under a curve in a logarithmic scale or to calculate the growth rate of certain populations.

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