Consider the system of equations:
$$\dot x_1=x_2$$ $$\dot x_2=-q(t)x_1-p(t)x_2$$
(Sorry I don't know how to do subscript notation for the 1's and 2's, an edit would be appreciated. Also the $x_1$ and $x_2$ should have dots above them, which I am not even sure of the meaning of...)
where $q(t)$ and $p(t)$ are continuous functions on all of $\Bbb R$. Find an expression for the Wronskian of a fundamental set of solutions.
So here's my (pathetic) attempt at a solution:
$$x_1=x_2\\ x_2=-q(t)x_1-p(t)x_2\\ x_2=-q(t)x_2-p(t)x_2\\ 0=x_2+q(t)x_2+p(t)x_2\\ 0=x_2(1+q(t)+p(t))$$
I don't really know how to attack this problem...