Resolve Initial Value Problem | Find y0 for Diverging Solutions

newtomath
Messages
37
Reaction score
0
I am having trouble with the below problem:

y'-(3/2)y= 3t+ 2e^t, y(0)= y0. fine value of y0 that separate solutions that grow positively and negatively as t=> infinity.

I found p(t) to be -3/2, u(t) to be e^-3t/2
=> e^-3t/2*y' - 3y/2( e^-3t/2)= e^-3t/2(3t+ 2e^t)
=> -2 -4e^t + ce^ 3t/2
where I found c = y0+6/ e

Do you guys see any errors in my math so far? i am confused as to find y0 where the solutions diverge (pos. vs neg)

Thanks
 
Physics news on Phys.org
I get

y=-2t - \frac 4 3 -4e^t+(y_0+\frac{16}{3})e^{\frac 3 2 t}

so you might want to check your arithmetic. Since you have a negative times one exponential and a positive times the other, that might have something to do with the positive vs negative thing.
 
@LC youre right, thanks. I am a little rusty in my integral rules. Got it now
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top