- #1
iRaid
- 559
- 8
Homework Statement
Apply the definition in (1) to find directly the Laplace transforms of the functions described (by formula or graph).
1) f(t)=t
Homework Equations
The Attempt at a Solution
Seems pretty easy... Question is, I don't understand the directions exactly.. Am I allowed to use the tables or do I have to solve the transform? Anyway this is how I solved, but i got stuck..
$$\mathcal{L}(f(t))=\int_0^{\infty}e^{-st}f(t)dt=\int_0^{\infty}te^{-st}dt$$
Then using an integration by parts, u=t and dv=e-stdt, I get:
$$\frac{-te^{st}}{s}\bigg|_0^{\infty}-\int_0^{\infty}\frac{-e^{st}}{s}dt=\left(\frac{-te^{st}}{s}-\frac{e^{s}t^{s}}{s^{2}}\right)\bigg|_0^{\infty}$$
Is that right up to there and what do I do after?