Integration by parts evaluation

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Homework Help Overview

The discussion revolves around the evaluation of an integral using integration by parts, specifically the integral of the form ∫xax. Participants are exploring the steps involved in the integration process and addressing potential errors in the calculations.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to apply integration by parts and seeks confirmation on their approach. Some participants question the correctness of the derived expressions and the simplifications made, particularly regarding logarithmic identities.

Discussion Status

Participants are actively discussing the steps taken in the integration process, with some providing feedback on the correctness of the expressions. There is a recognition of different interpretations of logarithmic properties, and guidance is being offered without reaching a definitive conclusion.

Contextual Notes

There is a focus on ensuring the correct application of integration techniques and the handling of logarithmic expressions. Participants are navigating through potential misunderstandings related to the properties of logarithms and constants in integration.

delapcsoncruz
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∫xax

u=x
du=dx
dv=axdx
v=ax/lna

= xax - ∫axdx/lna

is my solution right?
my problem now is how to integrate the expression xax - ∫axdx/lna
please help..
 
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Seems correct to me, you just need to evaluate the 2nd term, the integral, you know how to do integrate a^x as you've already done it, 1/ln(a) is just a constant.
 
The1337gamer said:
Seems correct to me, you just need to evaluate the 2nd term, the integral, you know how to do integrate a^x as you've already done it, 1/ln(a) is just a constant.

ok this what I've got...

=xax - ∫axdx/lna

=xax - 1/lna∫axdx

=xax - (1/lna) (ax/lna)

=xax - ax/2lna

is that right that (lna)(lna) = 2lna?
or it is just (lna)(lna) = (lna)(lna)
 
It's the bottom line as:

2ln(a) = ln(a^2)

What you have is ln(a)ln(a) = (ln(a))^2.
 
The1337gamer said:
It's the bottom line as:

2ln(a) = ln(a^2)

What you have is ln(a)ln(a) = (ln(a))^2.

but , was my answer correct?
 
xa^x - a^x/(2lna) isn't correct, xa^x - a^x/(ln(a))^2 is.
 
The1337gamer said:
xa^x - a^x/(2lna) isn't correct, xa^x - a^x/(ln(a))^2 is.

ah ok..thank you very much!
 

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