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Extremum Function of a Functional

  • Thread starter Shantih
  • Start date
  • #1
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Homework Statement



J(f)=[itex]\int[/itex] 2xf−f′2+3f2f′dx
f(0)=0,f(1)=−1.

Homework Equations



Ff-[itex]\frac{d}{dx}[/itex]Ff'=0

The Attempt at a Solution



Ff=2x+6f f''
Ff'=-2f' + 6f2

Plugging in, I get:
2x+6f f''- [itex]\frac{d}{dx} (-2f' + 6f2)

2x+6f f''-12f f'-2f''=0

Which doesn't look correct to me.
I'm guessing my mistake was in the differentiation, but I don't see it.
 

Answers and Replies

  • #2
2
0
I figured it out, algebra errors.
 

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