Integral of unit impulse function?

In summary, the conversation discusses the use of the unit impulse function δ to represent instantaneous changes in a system and its integration with other functions. The main point is that the integral of δ results in a value of 1 and is only nonzero at t=0. The conversation also touches on different theoretical approaches to explain the behavior of the delta function.
  • #1
Abdulwahab Hajar
56
2

Homework Statement



let's use this symbol to denote the unit impulse function δ
When integrating the unit impulse function (from negative infinity to infinity) ∫δ(t) dt I know that this results in a value of 1 and is only nonzero at the point t = 0.

However for example take this integral into consideration ∫δ(t) e-jωt
since the delta function is only nonzero at the point zero, we only evaluate this multiplication at the point 0 which yields e0 which is 1.

but how can we do that, the integral involves two functions dependant on time shouldn't we integrate from limits for example 0- to 0+ and integrate it by parts or something like that?

Homework Equations



∫δ(t) = 1 at t =0

The Attempt at a Solution



My attempt is attempting to explain it above
Thank you
 
Physics news on Phys.org
  • #2
There are a few different ways to put the Derac delta function (generalized function, distribution) on a solid theoretical basis (see https://en.wikipedia.org/wiki/Dirac_delta_function). The result and goal of all of them is that ∫δ(t)f(t)dt = f(0).
 
  • Like
Likes Abdulwahab Hajar
  • #3
FactChecker said:
There are a few different ways to put the Derac delta function (generalized function, distribution) on a solid theoretical basis (see https://en.wikipedia.org/wiki/Dirac_delta_function). The result and goal of all of them is that ∫δ(t)f(t)dt = f(0).
thank you, you were very helpful...
loving the profile pic btw!
 

1. What is the unit impulse function?

The unit impulse function, also known as the Dirac delta function, is a mathematical function that is defined as zero everywhere except at the origin, where it takes on an infinite value. It is often used in engineering and physics to model point-like forces or impulses.

2. What is the integral of the unit impulse function?

The integral of the unit impulse function is equal to one. This is because the function is defined as zero everywhere except at the origin, where it takes on an infinite value. Integrating over this infinite value results in a finite value of one.

3. How is the unit impulse function used in signal processing?

In signal processing, the unit impulse function is used to represent a discrete-time signal that has a value of one at a specific sample and zero everywhere else. This is useful for analyzing and manipulating signals in the time domain.

4. Can the unit impulse function be approximated by other functions?

Yes, the unit impulse function can be approximated by a sequence of rectangular pulses that become narrower and taller as the number of pulses increases. This sequence of pulses is known as the Kronecker delta function and is often used in practical applications.

5. What is the relationship between the unit impulse function and the delta function?

The unit impulse function and the delta function are two different names for the same mathematical function. The term "unit impulse function" is more commonly used in engineering and physics, while the term "delta function" is more common in mathematics and signal processing.

Similar threads

  • Calculus and Beyond Homework Help
Replies
0
Views
173
  • Calculus and Beyond Homework Help
Replies
7
Views
291
  • Calculus and Beyond Homework Help
Replies
6
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
286
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
Replies
1
Views
614
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
12
Views
995
  • Calculus and Beyond Homework Help
Replies
17
Views
993
  • Calculus and Beyond Homework Help
Replies
6
Views
398
Back
Top