Consider the following two$-$dimensional velocity fields. Determine if the velocity field is solenoidal, and if it is irrotational. Justify your answers. $(a$ is a constant$).$

$\backslash$table$[[$Velocity field,Solenoidal?,Irrotational?$],[u=\frac{ax}{x^2+y^2},v=\frac{ay}{x^2+y^2},,],[u=\frac{ay}{x^2+y^2},v=-\frac{ax}{x^2+y^2},,]]$