Need help solving a differential equation

Click For Summary
SUMMARY

The discussion centers on solving the linear differential equation dy/dx = 2y + x^2 + 5. The user correctly reformulates the equation into the standard linear form dy/dx + -2y = x^2 + 5 and identifies the need to compute the integral of (x^2 + 5)e^-2x dx. The solution involves using integration by parts twice to handle the term x^2e^-2x, leading to a successful resolution of the problem.

PREREQUISITES
  • Understanding of linear differential equations
  • Familiarity with integration techniques, specifically integration by parts
  • Knowledge of exponential functions and their integrals
  • Ability to manipulate and rearrange differential equations
NEXT STEPS
  • Study the method of integrating linear differential equations
  • Practice integration by parts with various functions
  • Explore the use of integrating factors in differential equations
  • Learn about the applications of differential equations in real-world scenarios
USEFUL FOR

Students studying calculus, particularly those focusing on differential equations, as well as educators and tutors looking for practical examples of solving linear differential equations.

lilmul123
Messages
39
Reaction score
0

Homework Statement



dy/dx = 2y + x^2 + 5.

This is a linear differential equation, so I know I need to use the definition of it which is y*e^integral(P(x)) dx = integral(f(x)*e^int(P(x)) dx.


I tried to get it into this form, so I tried to change the equation to dy/dx + -2y = x^2 + 5. Eventually, the right side of my linear equation for solving becomes the integral of (x^2 + 5)*e^-2x dx. The 5e^-2x dx is easy to integrate, but x^2*e^-2x dx is not. Did I form my initial equation correctly or am I really supposed to find the integral of that?
 
Physics news on Phys.org
Use integration by parts twice to integrate x2e-2x.
 
Yeah, I figured it out after looking at it for a while. Thank you.
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 25 ·
Replies
25
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K