Calculus: Solve the following differential equation

Click For Summary

Homework Help Overview

The discussion revolves around solving a differential equation of the form 8y'' - 4x = 0, with initial conditions specified as y=2 and y'=-3 at x=0. Participants are exploring the interpretation of the problem and the nature of the solution.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the process of finding the general solution to the differential equation and question whether the final answer should be a specific value or the function itself. There is also a consideration of how the initial conditions are stated and their implications for the solution.

Discussion Status

The discussion is ongoing, with some participants providing guidance on the interpretation of the problem and clarifying the nature of the solution. There is no explicit consensus on the final answer, but there is acknowledgment of the correctness of the approach taken by one participant.

Contextual Notes

Participants note that the wording of the initial conditions could be improved for clarity, indicating a potential source of confusion in the problem setup.

laker_gurl3
Messages
94
Reaction score
0
Solve the following differential equation:

8y'' - 4x = 0 Where y= 2 and y'=-3 and x= 0

first i did this:

y' = (1/4)x^2

y' = (1/4)x^2 - 3

then antideriv again to get the final answer:

y = (x^3)/12 - 3x + 2

is the final answer 2 or this one :y = (x^3)/12 - 3x + 2

THANK YOU!
 
Physics news on Phys.org
laker_gurl3 said:
Solve the following differential equation:

8y'' - 4x = 0 Where y= 2 and y'=-3 and x= 0

first i did this:

y' = (1/4)x^2

y' = (1/4)x^2 - 3

then antideriv again to get the final answer:

y = (x^3)/12 - 3x + 2

is the final answer 2 or this one :y = (x^3)/12 - 3x + 2

THANK YOU!

I think they are looking for the function y = f(x) rather than the specific value y = f(0). You would not need to solve the equation to find the latter, because it is given. The wording of the intitial conditions would be better stated as

Where y= 2 and y'=-3 at (or when) x= 0
 
so did i get it wrong this is all it said for the question:

Solve the following differential equation:

8y'' - 4x = 0 Where y= 2 and y'=-3 at x= 0
 
laker_gurl3 said:
so did i get it wrong this is all it said for the question:

Solve the following differential equation:

8y'' - 4x = 0 Where y= 2 and y'=-3 at x= 0

You did it correctly. I thought you were just trying to decide between the function you found and the specific value y = 2.

y = (x^3)/12 - 3x + 2 looks good to me.
 

Similar threads

Replies
1
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
Replies
62
Views
7K
Replies
8
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
24
Views
4K
  • · Replies 40 ·
2
Replies
40
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 20 ·
Replies
20
Views
4K