# DE#4

#### idontknow

$$\displaystyle s''-s'+s =e^{-2t}ss'^2$$.

#### skipjack

Forum Staff
One solution is $s = e^t$.

#### topsquark

Math Team
One solution is $s = e^t$.
You have answered a couple of these now. Is there a method to what you are doing or are you just awesome at what you do?

-Dan

idontknow

#### skipjack

Forum Staff
I consider whether the equation has, or implies, some type of equation that I have come across before, or that seems to be appreciably simpler. The next step is to look for simple solutions that might give a clue as to how a general solution might be found. For this problem, those solutions are $s = 0$, $s = e^t$ and $s = -e^t$, but the given equation looks quite awkward, and I haven't made further progress yet.

topsquark