For ten points, name this curve formed by a point on a circle rolling on a straight line.
Related forms of this curve are described as curtate and prolate, but in the standard type the cusps are separated by 2 times pi times the radius.  An early success of the calculus of variations was proof that it's the solution to the brachistochrone problem.  For ten points, name this curve formed by a point on a circle rolling on a straight line.
Related forms of this curve are described as curtate and prolate, but in the standard type the cusps are separated by 2 times pi times the radius.  
cycloid