圆柱螺线圆锥螺线 ●圆柱螺线标准方程 x=u·C0st y=a.sint (-0<t<+0 z=b.t ·圆锥螺线标准方程 x=a·t.cost y=b.t.sint (0<t<+o) t=c.t 99 圆柱螺线圆锥螺线 cos sin xa t ya t z bt  = ⋅  = ⋅  = ⋅  ( ) −∞ < < +∞ t  圆锥螺线标准方程 cos sin x at t y bt t z ct  = ⋅⋅  = ⋅⋅  = ⋅  (0 ) < < +∞ t  圆柱螺线标准方程