# I have some questions about ODE

1. Aug 30, 2008

### prison-rat

Hi. I have some important questions to solve until tomorrow night..

Can anyone solve them please ?

01
http://img356.imageshack.us/img356/4218/01hz1.jpg [Broken]

02
http://img356.imageshack.us/img356/4851/02yn6.jpg [Broken]

03
http://img356.imageshack.us/img356/5762/03pm9.jpg [Broken]

04
http://img204.imageshack.us/img204/7753/04gr4.jpg [Broken]

Thank you

Last edited by a moderator: May 3, 2017
2. Aug 30, 2008

### tiny-tim

Welcome to PF!

Hi prison-rat! Welcome to PF!

Show us what you've done and where you're stuck, and then we'll know how to help you!

3. Aug 31, 2008

### prison-rat

I solved 1-2 but ımnot sure the re true.
3-4 Im trying
here first 2

thanks

Last edited by a moderator: May 3, 2017
4. Aug 31, 2008

### HallsofIvy

Staff Emeritus
You are fine until 2b
$$\int \frac{dy}{1- 2y}\ne ln(1- 2y)+ C$$
Let u= 1- 2y and substitute.

5. Aug 31, 2008

### HallsofIvy

Staff Emeritus
Numbers 3 and 4 look fairly standard. Do you know what an "exact differential" is?

For number 4, notice that there are no odd powers in the characteristic equation.