using chain rule find the derivative of y=xsin1/x

y' = sin(1/x) dx/dx + x d(sin(1/x))/dx

= sin (1/x)+ x cos(1/x)d(1/x)/dx
= sin (1/x)+ x cos(1/x)(-1/x^2)
= sin(1/x) - (1/x)cos(1/x)