$(15$ points$)$

It can be shown that $y_1=2$ and $y_2=co{s}^2(7x)+si{n}^2(7x)$ are solutions to the differential equation $7x^{5}sin(2x)D^{2}y-2x^{2}cos(7x)Dy=0$ on $(0,\frac{}{4}).$

What does the Wronskian of $y_1,y_2$ equal on $(0,\frac{}{4})?$

$W(y_1,y_2)=$ on $(0,\frac{}{4}).$

$1.$ Is $\{y_1,y_2\}$ a fundamental set for $7x^{5}sin(2x)D^{2}y-2x^{2}cos(7x)Dy=0$ on $(0,\frac{}{4})?$