How Does the Delta Function and Its Derivative Interact with Shifted Functions?

AI Thread Summary
The discussion focuses on proving the relationship between the delta function and its derivative when interacting with shifted functions. The key equation to prove is that the integral of the derivative of the delta function multiplied by a shifted function equals the negative derivative of that function evaluated at the shift. The solution involves applying integration by parts and the integral definition of the delta function. The steps show that the integral of δ'(x) * f(x-a) simplifies to f(-a) - f'(-a). This illustrates the interaction between the delta function, its derivative, and shifted functions in the context of distribution theory.
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Homework Statement


Prove the following
'()( − ) = −′()
-∞δ'(x)*f(x-a) = -f'(a)

Homework Equations


-∞δ'(x-a)*f(x) = f(a)

The Attempt at a Solution


[/B]
-∞ δ'(x)*f(x-a) = ∫δ(x)*f(x-a)dx-∫f'(x-a)*δ(x)dx = f(-a) - f'(-a)
Went from 1st to second by integration by parts
Used integral definition of delta function to go to 3rd part
 

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The Attempt at a Solution



1) ∫-∞ ∞δ'(x)*f(x-a)
2) = ∫δ(x)*f(x-a)dx-∫f'(x-a)*δ(x)dx
3) = f(-a) - f'(-a)
Went from 1st to second by integration by parts
Used integral definition of delta function to go to 3rd part

Made above easier to read
 
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