Recent content by JonForbes

  1. J

    What is the Laplace Transform of cos(3t)*u(t)?

    Homework Statement I need to know what the laplace transform is for f(t) * u(t) More specifically, h(t) = cos(3t)*u(t) Homework Equations I know that f(t-to) * u(t-to) = e-tos * F(s)The Attempt at a Solution So, f(t) = cos(3t) F(s) = s/(s2 + 9) In the formula I gave in (2), I would...
  2. J

    Derivative of the step function: u(-t)

    Thanks, just needed someone with more knowledge than me to confirm it.
  3. J

    Derivative of the step function: u(-t)

    I need to know the derivative of the step function u(-t). I believe it is: -&(-t) where & represents the impulse function. Is this correct? Thanks.