How Does the Step Function Relate to the Derivative of the Dirac Delta Function?

AI Thread Summary
The discussion centers on the relationship between the step function θ(x) and the Dirac delta function δ(x). It establishes that the derivative of the step function, defined as 1 for x > 0 and 0 for x ≤ 0, is equal to δ(x). Participants explore the connection to the Heaviside step function, noting that the Heaviside function is 1 for x ≥ 0, which complicates the comparison. A hint is provided to consider the expression 1 - θ(x) to facilitate understanding. The conversation emphasizes the importance of recognizing the nuances in defining these functions for proper mathematical analysis.
CasualDays
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Derivative Using Dirac Delta Function

Homework Statement


Let \theta(x) be the step function:

\theta(x) be equivalent to

1, if x > 0
0, if x \leq 0

Show that \frac{d \theta }{dx} = \delta(x)


Homework Equations


In the previous portion I was able to prove
x \frac{d}{dx} (\delta(x))= -\delta(x)


The Attempt at a Solution


I thought the problem was a heavyside problem but upon closer inspection, I noticed that on the heavyside step function it is 1 when x \geq 0.

So how do I resolve this? Is there a way to change it so that it looks like a heavyside function, because that makes the problem much more convenient.:smile:
 
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Hi CasualDays! :smile:

(have a theta: θ and a delta: δ :smile:)

Hint: what is 1 - θ(x)? :wink:
 
tiny-tim said:
Hi CasualDays! :smile:

(have a theta: θ and a delta: δ :smile:)

Hint: what is 1 - θ(x)? :wink:


It's always the easy solutions that allude me..:biggrin:
 
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