In cylindrical coordinates

grad$=i_{r}de\frac{l^{}}{d}$elr$+i_{}^{}(\frac{1}{r})de\frac{l}{d}el+i_z^{}de\frac{l}{d}$elz, and

a$)$ Determine grad$*grad$ and grad$*V^{\text{'}}$

b$)$ show that grad$*(gradV)=0$