1. Verify it
2. x1(t) = -3/2 exp(2t) + 7/2 exp(4t), x2(t) = -9/2 exp(2t) + 7/2 exp(4t)
3. 1. a vector{1}{2} exp(-t) + b vector{2}{1} exp(2t)
   2. a vector{2}{1} exp(t) + b (vector{2}{1} t exp(2t) + vector{1}{0} exp(t))
   3. a exp(t) vector{cos(2t)}{cos(2t)+sin(2t)} + b vector{sin(2t)}{sin(2t)-cos(2t)}
4. alpha=0 is critical value