Problem $1$: $(4-$marks$)($Please show all your work.$)$

Given the potential field, $V=2x^{2}y-5z,$ find:

a$)V$ at the point $P(-4,3,6)$

b$)E$ at the point $P(-4,3,6)$

c$){}_v$ at the point $P(-4,3,6)$

d$)$ Electric potential energy stored in the region $1$