Describe in words the surface whose equation is given.

$=\frac{2}{3}$

the bottom haif of the right circular cone with vertex at the origin and axis the negative $2-$axis

the plane perpendicular to the $xy-$plane passing through $y=\frac{\sqrt[\phantom{2}]{3}}{2}x,$ where $x0$

the plane perpendicular to the $xz-$plane passing through $x=\frac{\sqrt[\phantom{2}]{3}}{2}x,$ where $x0$

the plane perpendicular to the $yz-$plane passing throwgh $z=\frac{\sqrt[\phantom{2}]{3}}{2}y,$ where $y0$

the top half of the right circular cene with vertex at the origin and axis the sositive $2$ axis