Am learning DE "second solutions"
the answer book sets constant 1 to 1 and constant 2 to 0 and gets a solution for y2.
why is c2 not set to 1, which would give y2=e^2x rather than y2=xe^2x.
what if c1 and c2 are both set to 1?
is this arbitrary?
Can you teach me how to get u? I'm trying to learn too.
>>8188376
You should show the whole problem, not just the solution.
Looks like it's a non homogeneous equation, and that e^2x would be linearly dependent, not a solution.
>>8188489
It'd be helpful if you give some fugging context but for now I'll just throw random facts of what I've read in the past. "[math]u(x)[/math]" is probably shorthand being used to refer to the "integrating factor" in ODEs.
>>8188376
This is what happens when you teach linear algebra separately from differential equations.
People fuck up easy things like this.
>>8188489
You choose u appropriately based on your prior knowledge of useful substitutions.
>>8188556
Rando here. I'm heading into DiffEq. Do you have a textbook recommendation that blends in linear algebra? The couple of books I've seen appear to avoid it.
>>8188567
You could always supplement yourself with a linear algebra text and refer to it whenever you need it. I'd recommend something like Lay because it's pretty easy to understand for just about everybody. If you're going to take a super rigourous course though, don't use it at all.
>>8188376
Given an nth order homogenous equation, the general solution is a linear combination of n particular (linearly independent) solutions.
So for a second-order homogenous DE, if you have two solutions, y1 and y2, then the general solution to the homogenous DE is y = c1y1 + c2y2.
In your case you have the solutions y1 = xe^2x and y2 = e2x.
Writing these as a linear combination gives us the general solution:
y = c1xe^2x + c2e^2x
A group G having a faithful complex 1-dimensional representation is cyclic, right? Since the values are roots of unity and the group of all roots of unity is cyclic.
IF y=y2, THEN c1=1 AND c2=0
IF y=y, THEN c1=c1 AND c2=c2
psi is goverened by the Schrodinger equation.
I can't do b).. I still have the potential term in additiion to the spatial derivatives. help
>>8190044
kys this is literally explained + proved in the first chapter of any decent QM book
>>8190055
This is a decent QM book and this was not explained or proved in the first chapter. Also I'd much rather do it myself.
>>8190060
>Also I'd much rather do it myself.
This is false. Otherwise, you wouldn't be shitposting homework on here.
>>8190074
I've done it now and it's not homework. I just wanted a pointer, not the whole answer. This is SQT so it's hardly shitposting.
Completely off topic, but fuck it; that's what this thread is for. What's a good background color for an academic webpage? I'm currently using C1E1A6 (a really laid back green) for the background and black text.