How to find the convolution of e^t and sin(2t)

  • Thread starter Thread starter errordude
  • Start date Start date
  • Tags Tags
    Convolution
Click For Summary
SUMMARY

The discussion focuses on finding the convolution of the functions f(t) = e^t and g(t) = sin(2t). The convolution is defined as f * g = ∫_0^t f(α)g(t - α)dα. Participants emphasize the importance of showing initial effort before seeking help and clarify that Fourier transforms are unnecessary for this problem. A practical hint is provided to simplify the integration process by substituting g(t - α) with e^(t - α).

PREREQUISITES
  • Understanding of convolution in the context of continuous functions
  • Familiarity with integration techniques
  • Knowledge of periodic functions and Fourier series
  • Basic concepts of function substitution in integrals
NEXT STEPS
  • Study the definition and properties of convolution in detail
  • Practice integrating exponential and trigonometric functions
  • Explore Fourier series representation of periodic functions
  • Learn about the application of convolution in signal processing
USEFUL FOR

Students in mathematics or engineering fields, particularly those studying signal processing, differential equations, or Fourier analysis, will benefit from this discussion.

errordude
Messages
17
Reaction score
0

Homework Statement


Hi, can anyone help me to determine the convolution for the 2π periodic function f(t)=e^t and sin2t
 
Physics news on Phys.org


Someone can probably help you but I doubt they will until you show some effort at working this for yourself.

According to the rules of this forum (https://www.physicsforums.com/showthread.php?t=5374),
On helping with questions: Any and all assistance given to homework assignments or textbook style exercises should be given only after the questioner has shown some effort in solving the problem. If no attempt is made then the questioner should be asked to provide one before any assistance is given. Under no circumstances should complete solutions be provided to a questioner, whether or not an attempt has been made.​
 


well i know how to write e^t as a 2π periodic Fourier series but then what?
 


What's the definition of the convolution of two functions? When you posted this problem, you deleted sections 2 and 3 about Relevant equations and your efforts at solving the problem.
 


You don't need to use FOurier transforms for this problem. It is quite simple indeed, just go to the definition of the convolution of two functions, as was suggested here all along:

f\ast g=\int_0^tf(\alpha)g(t-\alpha)d\alpha

Now just substitute your functions instead of g and f. Hint: inside the integral i would let g(t-alfa)=e^(t-alfa), it makes the integration process easier. You know how to integrate, right?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 19 ·
Replies
19
Views
29K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 11 ·
Replies
11
Views
7K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K