f $y=a\cos \left(\log x\right)+b\sin \left(\log x\right)$ then $x^2{y}_2+x{y}_1=$

$\begin{array}{l}y=a\cos \left(\log x\right)+b\sin \left(\log x\right)\\ y_1=\frac{-a\sin \left(\log x\right)}{x}+\frac{b\cos \left(\log x\right)}{x}\\ x{y}_1=-a\sin \left(\log x\right)+b\cos \left(\log x\right)\\ x{y}_2+y_1=\frac{-a\cos \left(\log x\right)}{x}-\frac{b\sin \left(\log x\right)}{x}\\ x^2{y}_2+x{y}_1=-[a\cos \left(\log x\right)+b\sin \left(\log x\right)]\\ x^2{y}_2+x{y}_1=-y\end{array}$