Integration by parts expression help

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Homework Help Overview

The discussion revolves around the integration of the expression ∫ x³ e^(x²) dx, focusing on the application of integration by parts and the challenges encountered in finding suitable u and dv components.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply the "LIATE" rule for integration by parts but questions the feasibility of integrating dv = e^(x²) dx. They also explore an alternative approach by switching u and dv but express doubts about the resulting integral.

Discussion Status

Participants are actively discussing various approaches, including a suggestion to change variables and perform a u-substitution. There is no explicit consensus on the best method, but several lines of reasoning are being explored.

Contextual Notes

Participants note the complexity of integrating e^(x²) and the challenges posed by the terms involved in the integration by parts setup. There are indications of missing information or assumptions that may affect the approaches being considered.

AStaunton
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the expression to integrate is:

[tex]\int x^{3}e^{x^{2}}dx[/tex]

and in the spirit of "LIATE" I set my u and dv as the following:

[tex]dv=e^{x^{2}}dx[/tex]

[tex]u=x^{3}[/tex]

however, doing this that I integrate [tex]dv=e^{x^{2}}dx[/tex] in order to get v...and unless I'm missing something, this does not seem like an easy integral! a u substition won't work as i'd need an x^1 term multiplying by the e^x^2...

and going the other way and setting dv=x^3dx and u=e^x^2 and plugging into int,by parts formula gets:

[tex]\frac{x^{4}}{4}e^{x^{2}}-\int\frac{x^{4}}{4}2xe^{x^{2}}dx[/tex]

and I don't think further integration by parts will help with this new integral..

any advice appreciated.
 
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correction of typo:



however, doing this REQUIRES that I integrate [tex]dv=e^{x^{2}}dx[/tex] in order to get v...
 
change variable x^2->u
 
Perform a u-substitution with u = x3, and then integrate by parts.
 

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