Hi!
Here is the code in Mathematica 7.
sphere = RegionPlot3D[(x^2 + y^2 + z^2 <= 1) && (x < 0 || y < 0 ||
z < 0), {x, -1, 1}, {y, -1, 1}, {z, -1, 1}, Mesh -> False,
Boxed -> False, Axes -> True, AxesOrigin -> {0, 0, 0},
AxesLabel -> {X, y, Z}, PlotPoints -> 50...