Let us denote by $y_1(t)$ and $y_2(t)$, 2 solutions of the equation
$y'' + p(t)y' + q(t)y = 0$, with $p$, $q$ continuous
Determine
$\frac{d}{dt}W(y_1, y_2)(t)$
as a function of $W(y_1, y_2)(t)$, where $W(y_1, y_2)$ is the Wronskian of $y_1$ and $y_2$ (we do not
require/need the explicit computation of $y_1$ and $y_2)$.