Signal and Systems: Verify the impulse response of this system

Click For Summary
SUMMARY

The impulse response of the system described by the differential equation $$\frac{dy(t)}{dt} + 2y(t) = x(t)$$ is confirmed to be $$h(t) = e^{-2t}u(t)$$. The initial attempt to verify this response involved incorrect simplification, specifically neglecting the product rule when differentiating $$e^{-2t}u(t)$$. The correct application of the product rule leads to the proper verification of the impulse response, resulting in a true statement rather than an erroneous one.

PREREQUISITES
  • Understanding of linear time-invariant (LTI) systems
  • Familiarity with impulse response and its significance in system analysis
  • Knowledge of the product rule in calculus
  • Basic concepts of the Heaviside step function, $$u(t)$$
NEXT STEPS
  • Study the application of the product rule in differentiating functions involving the Heaviside step function
  • Explore the properties of linear time-invariant systems and their impulse responses
  • Learn about the Laplace transform and its role in analyzing differential equations
  • Investigate the relationship between impulse response and system stability
USEFUL FOR

Students and professionals in electrical engineering, control systems, and applied mathematics who are analyzing linear systems and their responses to inputs.

SumDood_
Messages
39
Reaction score
6
Homework Statement
Verify that the impulse response of this system is h(t) = e^(-2t)u(t)
Relevant Equations
Impulse response => x(t) = impulse
Verify that the impulse response of this system is ##h(t) = e^{-2t}u(t)## for the following system
$$\frac{dy(t)}{dt} + 2y(t) = x(t)$$

So this is what I did first,
$$
\begin{align}
\frac{dh(t)}{dt} + 2h(t) &= \delta (t) \\
\frac{d}{dt}e^{-2t}u(t) + 2e^{-2t}u(t) &= \delta (t) \\
-2e^{-2t}u(t) + 2e^{-2t}u(t) &= \delta (t) \\
0 &= \delta (t)
\end{align}
$$
Of course, my solution is wrong. Honestly, at the beginning, I didn't know what I am supposed to get that would verify that the impulse response of the system is ##h(t) = e^{-2t}u(t)##.
So, first, what mistake did I make when simplifying after substituting ##h(t)## and ##x(t)##?
Second, what form does the final statement need to take to actually verify the impulse response? Should I end up with a true statement?
 
Physics news on Phys.org
SumDood_ said:
Homework Statement: Verify that the impulse response of this system is h(t) = e^(-2t)u(t)
Relevant Equations: Impulse response => x(t) = impulse

Verify that the impulse response of this system is ##h(t) = e^{-2t}u(t)## for the following system
$$\frac{dy(t)}{dt} + 2y(t) = x(t)$$

So this is what I did first,
$$
\begin{align}
\frac{dh(t)}{dt} + 2h(t) &= \delta (t) \\
\frac{d}{dt}e^{-2t}u(t) + 2e^{-2t}u(t) &= \delta (t) \\
-2e^{-2t}u(t) + 2e^{-2t}u(t) &= \delta (t) \\
0 &= \delta (t)
\end{align}
$$
Of course, my solution is wrong. Honestly, at the beginning, I didn't know what I am supposed to get that would verify that the impulse response of the system is ##h(t) = e^{-2t}u(t)##.
So, first, what mistake did I make when simplifying after substituting ##h(t)## and ##x(t)##?
Second, what form does the final statement need to take to actually verify the impulse response? Should I end up with a true statement?
## \frac{d}{dt}[e^{-2t}u(t)] \neq -2e^{-2t}u(t) ##. Use the product rule, ##u(t)## is also a differentiable function of ##t##.
 
  • Like
Likes   Reactions: SumDood_
DaveE said:
## \frac{d}{dt}[e^{-2t}u(t)] \neq -2e^{-2t}u(t) ##. Use the product rule, ##u(t)## is also a differentiable function of ##t##.
Got the right solution, thanks!
 
  • Like
Likes   Reactions: berkeman and DaveE

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 17 ·
Replies
17
Views
6K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K