Integrating with Multiple Variables: How to Solve the Crazy Integration Problem?

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Homework Help Overview

The problem involves evaluating the integral of the product of a variable and the second derivative of a function, given specific values for the function and its derivatives at certain points. The subject area pertains to calculus, specifically integration techniques and the application of the fundamental theorem of calculus.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts integration by parts, defining \( u \) and \( v' \) and expressing the integral in terms of \( f' \) and \( f \). Some participants question the implications of the fundamental theorem of calculus regarding the integral of \( f' \). Others suggest revisiting the definitions and relationships between the functions involved.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the integral and its components. Some guidance has been offered regarding the fundamental theorem of calculus, which has prompted further reflection from the original poster.

Contextual Notes

The original poster expresses uncertainty about the next steps in their solution process and seeks clarification on the application of integration techniques. There is a sense of hesitation regarding their understanding of the concepts involved.

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Homework Statement



Let [tex]f[/tex] be twice differentiable with [tex]f(0)=6, f(1)=5,[/tex] [tex]f'(1)=2[/tex]
Evaluate the integral [tex]\int_0^{1}x f''(x) dx[/tex]


Homework Equations



[tex]\int uv' dx = uv = \int u'v dx[/tex]

The Attempt at a Solution



u = x and v' = f''(x)
so
u' = 1dx and v = f'(x)
so

[tex]xf'(x) - \int_0^{1}f'(x) dx[/tex]

from here I am not sure what to do... maybe parts again...
u = 1dx and v' = f'(x)
so
u' = 0? and v = f(x) //derivative of 1dx is 0 right?
so

[tex]xf'(x) - f(x) - \int_0^{1} 0 dx[/tex] ?

i really don't know. any help would be awesome!
 
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What does the fundamental theorem of calculus say about:

[tex]\int_0^1 f'(x)dx[/tex]

?:wink:
 
[tex]\int_0^1 f'(x)dx = f(1) - f(0)[/tex] ??
 
Yep.
 
wow that's awesome. now i feel retarded haha.
but seriosuly... thanks gabba!
 

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