ou have the electric potential function,

V$($x$,$y$,$z$)=$Axyz$+$By$2+$Cz$2,$V$($x$,$ y$,$ z$)=$ Axyz $+$ By$^2+$ Cz$^2,$V$($x$,$y$,$z$)=$Axyz$+$By$2+$Cz$2,$

where:

A$=4$V$/$m$3$A $=4\backslash ,\backslash$text$\{$V$/$m$\}^3$A$=4$V$/$m$3,$

B$=3$V$/$m$2$B $=3\backslash ,\backslash$text$\{$V$/$m$\}^2$B$=3$V$/$m$2,$

C$=5$V$/$m$2$C $=-5\backslash ,\backslash$text$\{$V$/$m$\}^2$C$=5$V$/$m$2.$

Find EzE$\_$zEz$$ at the point: $(2$m$,8\mathrm{.}7$m$,2$m$)(2\backslash ,\backslash$text$\{$m$\},8\mathrm{.}7\backslash ,\backslash$text$\{$m$\},2\backslash ,\backslash$text$\{$m$\})(2$m$,8\mathrm{.}7$m$,2$m$).$

Answer in units of V$/$m$\backslash$text$\{$V$/$m$\}$V$/$m$.$