# Homework Help: Impulse-Diffy eq.

1. Dec 14, 2009

### polarbears

1. The problem statement, all variables and given/known data
$$y''+y=\delta (t-2\pi )cos(t)$$
$$y(0)=0,y'(0)=1$$

2. Relevant equations

3. The attempt at a solution
The left side is (s^2+1)Y(s)-1=RHS

My problem is the fact that cosine is being multiplied by the delta function. I put it in the form of an intergral but I dont know what to do from there.

2. Dec 15, 2009

### HallsofIvy

Well, good! Delta functions usually make integrals trivial. What integral did you get?

3. Dec 15, 2009

### annoymage

hmm, i dont know what is this question, may i know, what topic should i study for this question?

4. Dec 15, 2009

### polarbears

Differential Equations -Laplace transforms

OHHHH waitttt does the delta function just determine the bound of my intergral?