In[132]:= <<Graphics`Shapes` In[133]:= Solve[{x^2+y^2+z^2\[Equal]1,x+y+z\[Equal]0},{x,y}] Out[133]= \!\({{x \[Rule] 1\/2\ \((\(-z\) - \@\(2 - 3\ z\^2\))\), y \[Rule] 1\/2\ \((\(-z\) + \@\(2 - 3\ z\^2\))\)}, {x \[Rule] 1\/2\ \((\(-z\) + \@\(2 - 3\ z\^2\))\), y \[Rule] 1\/2\ \((\(-z\) - \@\(2 - 3\ z\^2\))\)}}\) In[134]:= \!\(\(p1[z_] := {1\/2\ \((\(-