# Homework Help: Need help with some problems

1. Jan 30, 2007

### aparra2

hey guys i need help with this problem i tried to figure the out but most are homogeneous equations so i dont even know how to start and the newtons law of cooling i have no idea wut to do .thanks

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2. Jan 30, 2007

### cristo

Staff Emeritus
Welcome to the forums aparra2. Firstly, please note that all homework/textbook questions like this should be posted in the homework forums. Also note that you need to show your work before we can help you- forum rules.

For this question, your image is not clear, and I can't quite read the questions. Perhaps you could type the equations out? If you do, then I may be able to give you hints; but are you sure you don't know where to start? What do you know about how to solve these type of equations?

Last edited: Jan 30, 2007
3. Jan 30, 2007

### HallsofIvy

Is the first equation
$$p\frac{dp}{dt}= 1+ x+ 2y+ 2xy$$?
If so, are we to treat y as a constant?

Is the second equation
$$(1+ x^2)\frac{dp}{dx}+ 4xp= \frac{1}{1+x^2}$$?
If so, that is a linear equation. There is a standard formula for finding an "integrating factor". Do you know it?

Is the third equation
$$(p+ t^2y)\frac{dy}{dx}= 2tdt$$?
If so can we treat p as a constant?