# Brachistochrone Curve

### Brachistochrome Curve

According to the Wikipedia, a Brachistochrome curve is "is the one lying on the plane between a point A and a lower point B, where B is not directly below A, on which a bead slides frictionlessly under the influence of a uniform gravitational field to a given end point in the shortest time."

This example of a Brachistochrome curve has two examples using **DiffKt**. One uses the `DTensor`

api and
the other uses the `DScalar`

api. The examples call the `reverseDerivative()`

function in the **DiffKt** api to
use automatic differentiation to calculate the derivatives in the model used in the calculation.