Differential equation, is the book wrong or am I wrong?

Syringer

Lifer
Aug 2, 2001
19,333
3
71
It's a simple problem, and I don't see what I'm doing wrong..

You have to take the inverse laplace of

1/(s+2)^3 (EDIT)

So, simple enough it's t^2/2 * e^(-2t)

The book though says t^2/2 * e^(-t)

It has to be -2t right?
 

pillage2001

Lifer
Sep 18, 2000
14,038
1
81
Originally posted by: Syringer
It's a simple problem, and I don't see what I'm doing wrong..

You have to take the inverse laplace of

1/(s+2)^2

So, simple enough it's t^2/2 * e^(-2t)

The book though says t^2/2 * e^(-t)

It has to be -2t right?

I think it's -2t. I might be wrong. It's been 2 years since I took that class. :)
 

Syringer

Lifer
Aug 2, 2001
19,333
3
71
Originally posted by: Stojakapimp
you do know that t^2/2 is the same as t^1 which is the same at t, right?

No, I meant it's (1/2)t^2..

But whoops, I actually meant 1/(s+2)^3..
 

Stojakapimp

Platinum Member
Jun 28, 2002
2,184
0
0
Originally posted by: Syringer
Originally posted by: Stojakapimp
you do know that t^2/2 is the same as t^1 which is the same at t, right?

No, I meant it's (1/2)t^2..

But whoops, I actually meant 1/(s+2)^3..

in that case, you are right...it should be -2t