What Is the Role of u in This Laplace Transform Problem?

[drew1435]

Laplace inital value help!

Homework Statement

y''+4y'+4y=(t-2)u(t-2)exp-(t-2)
y(0)=1 y'(0)=-1

what is the use of this u i have worked the problem to the following

The Attempt at a Solution

(s+2)^2*L(y)(s)= 5s-1 ...

i have no idea how to approach the laplace ot the right side of the equation. some help please.

 

[rock.freak667]

L[f(t-a)H(t-a)]=e^-atF(s).

That will help you.