- #1

- 102

- 7

## Homework Statement

A damped harmonic oscillator is driven by a force of the form f(t)=h(t) t^2 Exp(-t), where h(t) is a Heaviside step function. The Oscillator satisfies the equation x''+2x'+4x=f(t). Use pencil-and-paper methods involving Fourier transforms and inverse transforms to find the

response of the oscillator, x(t), assuming that x(0)=0 and x'(0)=1.

## Homework Equations

The Fourier Transform F[f(t)]

The Inverse Fourier Transform F^(-1)[f(ω)]

Integration by parts

## The Attempt at a Solution

First thing I did was take the Fourier transform of the left hand side, which I'm sure I got correct. The part I'm stuck on is taking the fourier transform of f(t). I used integration by parts using

u=t^2/e^t dv=h(t)(Exp[i ω t])

du=(2t-t^2)/e^t v=πδ(ω)+i/ω

but now when I try to complete the integration, i get an integral that does not converge because of the i/ω. There have been multiple heaviside problems that I have been working on that all end up the same, and I'm not sure where to go from here.

Last edited: