The Cycloidal Pendulum

Huygens’ cycloidal pendulum: an elementary derivation

“…Cycloid is also associated to the solution of the celebrated brachistochrone problem [6], for which the principles of Calculus of Variation were first developed [2]. During last years a considerable deal of work has been done about elementary treatments of these 'magic' properties of cycloid, namely brachistochronism and tautochronism (see for instance [7][8][9][10][11][12][13]).…”