Find the particular solution of the differential equation [ x sin^2(y/x)- y ] d x + x d y =0 given that y =(π)/4, when x =1.

\[\begin{aligned} & {\left[\mathrm{x} \cdot \sin ^{2} \frac{\mathrm{y}}{\mathrm{x}}-\mathrm{y}\right] \cdot d \mathrm{x}+\mathrm{x} \cdot d \mathrm{y}=0} \\ & \Rightarrow \frac{d \mathrm{y}}{d \mathrm{x}}=\frac{\mathrm{y}}{\mathrm{x}}-\sin ^{2} \frac{\mathrm{y}}{\mathrm{x}} \end{aligned} \] $\displaystyle \Rightarrow \cot \frac{\mathrm{y}}{\mathrm{x}}=\log |\mathrm{x}|+1$