desolve_system problem with exp()/e^
Hi!
I'm trying to solve ode system: x'=-2x+2y+e^t, y'=-2x+3y+3e^t
This is what I tried in Sage:
reset()
var('t')
x = function('x', t)
y = function('y', t)
dgl1 = x.diff(t) == -2 * x + 2 * y + exp(t)
dgl2 = y.diff(t) == -2 * x + 3 * y + 3 * exp(t)
dgls = [dgl1, dgl2]
aw = [0, 0, -1]
S = desolve_system(dgls, [x, y], aw)
But I always get this error:
Traceback (click to the left of this block for traceback)
...
TypeError: ECL says: Maxima asks: Is ?g9271-1 positive, negative, or zero?
If I remove the exp(t) it works fine, also if I replace the exp(t) with for example 2^t Sage gives me a solution. I already tried using e^t instead of exp(t) and tried some assumptions (assume(x >= 0), assume(t >= 0), etc.). Anyone got an idea what I'm doing wrong? Thanks in advance!