Question

I'm confused on a Laplace Transform problem we did in class. I will post the problem and all the work. I'm looking for an explanation

Answer 1

In the picture I wrote my questions

Answer 2

those are standard formulas, u didn't get them ? see the table of laplace inverse....

Answer 3

And the answer to that will cost you $45/hour lol

Answer 4

and don't worry, u need not pay here anything....

Answer 5

L(e^{at})=1/(s-a)
so
L^{-1} of {1/(s-a)} = e^{at}

Answer 6

oh, u mean to ask, why s is taken -1 ? or -2 ?

Answer 7

I have the table. I guess I am not seeing how to apply them.

And @hartnn . Yes why isn't -2, -1 plugged into the left side and set equal. Why is it -2 = and -1 =

Answer 8

yup. it must be 22=-8B

Answer 9

Maybe I misunderstood what he was saying, but I copied the board exactly. I'll have to ask. That makes sense to me Hartnn

Answer 10

Ok fine! You see where you wrote your partial fractions? Those have to be matched up with the equations you're questioning. I probably have this exact problem worked out in my office. I'll go look

Answer 11

You're too kind @aerokat25

Answer 12

yeah, u put value of s on both sides...

Answer 13

So i look at my partial fractions and decide what laplace transforms to use? I see that

Answer 14

not exactly....partial fraction not dependent on transform...u use partial fraction and look for appropriate formula of inverse transform

Answer 15

Thanks for the clarification

Answer 16

I'm going to work out the problem with 22 and 19 and use the solution at the bottom of the page. I will post my answer when I finish

Answer 17

ok.

Answer 18

Yes what hart said....but I know u know that based on your work.

Answer 19

\[\frac{ 19 }{ 5 }e^{-t}-\frac{ 11 }{ 4 }e^{-2t}-\frac{ 1 }{ 20 }\cos 2t+\frac{ 3 }{ 20 }\sin 2t\]What is it equal to?

Answer 20

Hang on I found a question just like yours except its not solved with Laplace. Hang

Answer 21

Probably solved with undetermined coefficients. Thanks for your help

Answer 22

I have one very similar but I can't find it damn it. I have all my comps stuff out right now. I'm still looking.

Answer 23

Ok found something. How do I upload a pic onto this?

Answer 24

attach file button

Answer 25

that is equal to y

Answer 26

I should have known that. thx

Answer 27

welcomes ^_^

Answer 28

Did you figure it out @aerokat25