求导数

求导数

open System

let epsilon = 1e-10

let d (f : float -> float) x = 

    let dx = sqrt  epsilon

    (f (x + dx) - f(x - dx)) / (2.0 * dx)

[<EntryPoint>]

let main argv = 

//    printfn "%A" argv

    let f x = x ** 4.0 - x - 1.0

    printfn "%A" (d f 2.0)

    let f' = d f

    printfn "%A" (f' 2.0)

    

    Console.ReadLine() |> ignore

    0