[力] brachistochrone
(中英字幕) 【3Blue1Brown@Youtube】 最速降线(Brachistochrone)是数学史上的经典问题:物体沿什么形状的坡道从一点滑落到另一点所用时间最短?
line of quickest descent
... 投影线 line of projection 最速降线 line of quickest descent 参考线;基础(直线) line of reference ...
brachistochrone problem ; problem of brachistochrone ; brachistochrone curve
problem of brachistochrone
line of steepest descent