Question

Solve the differential equation

Answer 1

This looks like a very horrible and ugly method of undetermined coefficients.

Answer 2

Am I right?

Answer 3

Please tell me there is another way :( .

Answer 4

if you're doing differential equations... you're gonna have a bad time.

Answer 5

I am :( . That looks very messy to solve with undetermined coefficients :( .

Answer 6

Not that I can't do it, i'm just wondering if there is another way.

Answer 7

ya, i dont have a clue. with limited knowledge on differential equations. could you factor the left side like a quadratic polynomial?

Answer 8

No :P .

Answer 9

In fact you get complex roots when you find the characteristic equation.

Answer 10

Polynomial times exponential times cosine?
Ooo ya we definitely don't wanna do method of undetermined coefficients :(
Would take ages and ages to do.

I'm trying to remember what the other method is called. ummmmmmm

Answer 11

Variation of parameters?

Answer 12

The thing with the wronskian and all that shinanigans.

Answer 13

ya maybe that's it

Answer 14

No it's not it >.< .

Answer 15

ANd besides a wronskian is used to determine is the solutions are linearly independent or dependent.

Answer 16

wait a second. i thought wrongskian was a joke. lol

Answer 17

:P .

Answer 18

Okay, I guess i'm doing undetermined coefficients :( .

Answer 19

gonna be a long night it sounds.

Answer 20

why wouldn't variation of parameters work for this..?
I haven't done it in a while so I'm trying to remember the approach..

Answer 21

Yep :( . Well I have Coffee :P .

Answer 22

It probably would work but we haven't learnt it yet.

Answer 23

I could read ahead and use it I suppose...

Answer 24

coffee, the physics/math/engineering majors best friend

Answer 25

Engineering </3 .

Answer 26

same here. not as far as you yet though.

Answer 27

I'll see if there are any special tricks >.> .

Answer 28

What is wrong with undetermined coefficients?

Answer 29

have you tried pauls online notes

Answer 30

Nothing is wrong with undetermined coefficients but it's way too much work because i'm multiplying 3 guesses and then finding the first and second derivatives.

Answer 31

And yes I have :P . It's what I use to learn ;) .

Answer 32

Yah those derivatives are a little painful.
I would recommend using some shorthand like `c` for cosine and `s` for sine, maybe E for the exponential.. U dunno.
Saves you some writing.

Answer 33

I dunno*

Answer 34

Maybe yeah. It could get confusing when I use letters though :P .