Problems 1 to 6 below refer to a 2 X 2 system of the form
x'= Ax,       x=x(t)=(x_1 (t), x_2 (t))

where the matrix A is found in the given problem in the text.
For each system, ignore the problem in the text except for the matrix
and do the following instead:

(i) find the general solution (real form);
(ii) sketch in the phase plane the trajectories with ICs (1,0) and (0,1);
(iii) sketch the graphs of x_1 vs. t for the same ICs;
(iv) write down the fundamental matrix  exp(tA)

Matrices A:

1. p. 541, no. 1
2. p. 541, no. 3
3. p. 541, no. 19
4. p. 541, no. 35
5. p. 549, no. 1
6.  p.549, no. 5

The following three problems are from the text:

7. p.541, no. 46
8. p. 556, no. 12
9. p. 556, no. 14