(3)z=x2+y2,z=x2+y (4)z=y5-x2-y2,4z=x2+y 语句: Clearly1,g2,3 gl=ParametricPlot3DR Sqrt5*Sin u* Coslv sgrt 5]*Sin us invI, sqrt[5 *Cosu,u, 0, P1/43,v, 0, 2Pi), Shading->Falsel g2-ParametricPlot3D Sqrt[2 z*Coslv, sqrt[2*zSin v, 2 z, 120, 1,v,0, 2Pi Shading->False g3-ParametricPlot3D r* Coslv], rSin v ,0,r0, 1.5,v,0, 2Pi, Shading->Falsel Showg1, g2, g3, Shading->Falsel2 2 2 2 (3) z = x + y , z = x + y 2 2 2 2 (4) z = 5− x − y , 4z = x + y g3=ParametricPlot3D[{r*Cos[v],r*Sin[v],0},{r,0,1.5},{v,0,2Pi}, Shading->False] g2=ParametricPlot3D[{Sqrt[2 z]*Cos[v],Sqrt[2*z]Sin[v],2 z}, {z,0,1},{v,0,2Pi},Shading->False] Show[g1,g2,g3,Shading->False] g1=ParametricPlot3D[{Sqrt[5]*Sin[u]*Cos[v],Sqrt[5]*Sin[u]S in[v],Sqrt[5]*Cos[u]},{u,0,Pi/4},{v,0,2Pi},Shading->False] 语句：Clear[g1,g2,g3]