# Homework Help: Laplace Unit Step function

1. Dec 4, 2012

### gbuitkus

1. The problem statement, all variables and given/known data
y''-4y'-32y={1 when 0<=t<1 and 0 when 1<=t
y(0)=y'(0)=0

2. Relevant equations

3. The attempt at a solution
s2L(y) -4sL(y)-32 L(y)=u1(t)

I am just struggling to figure out if my unit step function is correct.

Solving for L(y) I get:
(e-s) / (s(s2 -4s-32))
but it says I am wrong so im pretty sure I am doing something wrong with the unit step function

2. Dec 4, 2012

### LCKurtz

You didn't explain what your notation $u_1(t)$ means. Is it $u(t-1)$? What you want on the right side is $u(t)-u(t-1)$.