Guessing the particular solution

Click For Summary
SUMMARY

The discussion focuses on finding a particular solution for the differential equation y(2) - 6y(1) = 25sin(6x) using the method of educated guessing. The initial guess for the particular solution was yp(x) = Asin(6x), which led to the equation -27Asin(6x) - 36Acos(6x) = 25sin(6x). The participant realized that a better guess would include both sine and cosine terms, suggesting the form yp = A*sin(6x) + B*cos(6x) for a more comprehensive solution.

PREREQUISITES
  • Understanding of differential equations
  • Familiarity with the method of undetermined coefficients
  • Knowledge of trigonometric functions and their derivatives
  • Ability to solve linear equations
NEXT STEPS
  • Study the method of undetermined coefficients in detail
  • Practice solving differential equations with non-homogeneous terms
  • Learn how to derive particular solutions for different types of functions
  • Explore the use of linear combinations of functions in particular solutions
USEFUL FOR

Students studying differential equations, educators teaching advanced mathematics, and anyone seeking to improve their problem-solving skills in mathematical analysis.

jdawg
Messages
366
Reaction score
2

Homework Statement


Find both a particular solution yp (via the method of educated guess) and a general solution y.
y(2)-6y(1)=25sin(6x)

Homework Equations

The Attempt at a Solution


This was my guess:
yp(x)=Asin(6x)
I then took derivatives, plugged them in, and simplified to get this:
-27Asin(6x)-36Acos(6x)=25sin(6x)
I'm stuck at this point! How do I solve for A? Or did I just make a bad guess for the particular solution?
 
Physics news on Phys.org
you end up with sin and cos terms, so it makes sense to try as particular solution also something with sin and cos terms:
y_p = A\sin(6x) + B\cos(6x)
 
  • Like
Likes   Reactions: jdawg
Ohhhh duh, thanks so much!
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
Replies
9
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 2 ·
Replies
2
Views
1K