• Support PF! Buy your school textbooks, materials and every day products Here!

Second-Order separable Differential equations

  • Thread starter Woolyabyss
  • Start date
  • #1
143
1

Homework Statement



Solve d2y/dt2 = dx/dt2, if x = 0 and dx/dt = 1 when t = 0

Homework Equations





The Attempt at a Solution



d2y = dx

I'm not exactly sure what to do here the fact that dt2 is under the denominator for both fractions is confusing memaybe its a typo? should it be d2y/dx2 = dx/dt?
 

Answers and Replies

  • #2
33,507
5,192

Homework Statement



Solve d2y/dt2 = dx/dt2, if x = 0 and dx/dt = 1 when t = 0

Homework Equations





The Attempt at a Solution



d2y = dx

I'm not exactly sure what to do here the fact that dt2 is under the denominator for both fractions is confusing memaybe its a typo? should it be d2y/dx2 = dx/dt?
That has to be a typo. dx/dt2 makes zero sense.

On a side note, try to make you posts clearer by at least indicating that some things are exponents. The simplest way is to use the caret or circumflex character (^), which is pretty much universally used for this purpose. For example, 3x2 and e^(rt).

A little nicer is to use the advanced menu (click Go Advanced below the input area. For exponents, click the X2 button. You can do subscripts with the X2 button.

For fancier stuff, you can use LaTeX to write things like ##10x^2## and even fancier stuff. Here's a link to a summary of how to do that: https://www.physicsforums.com/showthread.php?t=617567 - item 2 on the list.
 
  • #3
143
1
That has to be a typo. dx/dt2 makes zero sense.

On a side note, try to make you posts clearer by at least indicating that some things are exponents. The simplest way is to use the caret or circumflex character (^), which is pretty much universally used for this purpose. For example, 3x2 and e^(rt).

A little nicer is to use the advanced menu (click Go Advanced below the input area. For exponents, click the X2 button. You can do subscripts with the X2 button.

For fancier stuff, you can use LaTeX to write things like ##10x^2## and even fancier stuff. Here's a link to a summary of how to do that: https://www.physicsforums.com/showthread.php?t=617567 - item 2 on the list.
Alright thanks, If i were to assume they meant d^2y/dt^2 = dx/dt

would I be correct in saying I could integrate both sides and it would be dy/dt = x + c?
 
  • #4
33,507
5,192
It might be better to figure out what the exact problem should be. Can you contact your instructor to get this clarified?
 
  • #5
143
1
It might be better to figure out what the exact problem should be. Can you contact your instructor to get this clarified?
No im afraid not I'll just leave ut for now. Thans anyway
 
  • #6
HallsofIvy
Science Advisor
Homework Helper
41,833
955
The difficulty is that you have a single equation for two unknown functions, x and y. That is not sufficient. You need another equation.
 

Related Threads on Second-Order separable Differential equations

Replies
4
Views
1K
  • Last Post
Replies
1
Views
857
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
5
Views
821
  • Last Post
Replies
1
Views
693
Replies
3
Views
1K
Replies
4
Views
2K
  • Last Post
Replies
3
Views
899
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
836
Top