2. A vector field is given by A(x, y, z)=A_{0} \hat{\mathbf{z}}+A_{1} \frac{\mathbf{r} \times \hat{\mathbf{z}}}{r^{2}} where A0 and A1 are constants, and r=\sqrt{x^{2}+y^{2}+z^{2}} (a) Calculate div A. (b) Calculate curl A.