Integration by part not working

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Homework Help Overview

The discussion revolves around the integration of three specific integrals involving exponential functions and polynomial terms, specifically from 0 to 1. The integrals presented include terms with both negative and positive coefficients, and there is a focus on the challenges faced in integrating these expressions.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the integrability of the expressions, with some questioning the variable of integration and the setup of the integrals. There is mention of using integration by parts, and one participant suggests a potential correction regarding the variable of integration.

Discussion Status

The conversation has evolved with participants clarifying the integrals and addressing potential misunderstandings. One participant indicates they have resolved their issue by recombining parts of the integral and applying integration by parts, although the specifics of this resolution are not detailed.

Contextual Notes

There is an indication that the original integrals may have been miswritten, leading to confusion about their integrability. The variable of integration was initially noted as 't' but later corrected to 'x'.

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Homework Statement


I have three integrals, from 0 to 1
∫ -4x5 ex3-x4dt
∫ 3x4ex3-x4dt
∫ 2tex3-x4dt

Homework Equations


Looks like they are not integrable, as ex3-x4 is not,
I tried by part, let say u =

The Attempt at a Solution


P_20161027_091741.jpg
 
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nysnacc said:

Homework Statement


I have three integrals, from 0 to 1
∫ -4x5 ex3-x4dt
∫ 3x4ex3-x4dt
∫ 2tex3-x4dt

Homework Equations


Looks like they are not integrable, as ex3-x4 is not,
I tried by part, let say u =

The Attempt at a Solution


View attachment 108079
If you have written the integrals exactly as they were given, they should all be very easy. The variable of integration in all three is t (based on the dt part).

As an example, ##\int e^x dt = e^x \int 1 dt = e^x (t + C)##
 
Oh, written wrong, should be dx,sorry
 
Should the last one you listed be ##\int_0^1 2xe^{x^3 - x^4}dx##?

Can you post a photo of the problems? I'm wondering if there's something you left out.
 
Yes, thanks I solved it tho, by recombine the parts in the integral and using by part
 

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