2. Prove that $y_1 = \cos(\ln x)$ and $y_2 = \sin(\ln x)$ are each solutions of the linear homogeneous equation
$x^2y'' + xy' + y = 0$.
Then, using the superposition principle, solve the following IVP:
$\begin{cases} x^2y'' + xy' + y = 0\\y(1) = 2\\y'(1) = -1 \end{cases}$