It can be shown that $y_1=e^{2 x}\sin(9 x)$ and $y_2=e^{2 x}\cos(9 x)$ are solutions to the differential equation $D^2 y -4 Dy + 85 y =0$ on $(-\infty,\infty)$.

What does the Wronskian of $y_1, y_2$ equal on $(-\infty,\infty)$?

$W(y_1,y_2)$ = on $(-\infty,\infty)$.

Yes No  1. Is $\{y_1,y_2\}$ a fundamental set for $D^2 y -4 Dy + 85 y =0$ on $(-\infty,\infty)$?