1. ## Laplace

Have a question im not to sure about, hopefully im in the right section.

d^2M/dt^2 =2delta(t-3)-2delta(t-6)

M=3 and dM/dt = 0 when t=0

I have to determine and sketch the function

So far i've took the lapace
s^2M-3M =2e^-3s - 2e^-6s is this right??

any pointers on what to do next

2. If this is a continuous DE, you need to recheck your Laplace transforms. Taking the Laplace transform of a derivative gives you some initial conditions, not just the transform of the original function. So, if $L[f(t)]=F(s)$, then $L[f'(t)]=sF(s)-f(0)$, and there is an analogous formula for the second derivative.

3. Another note: this question really belongs in the Differential Equations forum.