Sub Main()
    Dim x As Double
    Dim a As Single
    x = InputBox("Ââåäèòå çíà÷åíèå ïåðåìåííîé")
    a = InputBox("Ââåäèòå òî÷íîñòü")
    MsgBox ("" & Teylor(x, a))
End Sub

Function Teylor(x, a)
    Dim Sum As Integer, n As Integer
    Dim FactN As Long, Fact As Long
    Dim Prev As Double, Now As Double
    Dim Ans As Double
    Prev = 0
    Sum = 0
    n = 0
    Do While 1 = 1
        Fact = 1
        For i = 1 To 2 * n Step 1
            Fact = Fact * i
            Next i
        FactN = 1
        For i = 1 To n Step 1
            FactN = FactN * i
            Next i
        Now = ((-1) ^ n * Fact) / ((4) ^ n * ((FactN) ^ 2) * (2 * n + 1)) * (x) ^ (2 * n + 1)
        If Abs(Prev - Now) <= a Then
            Exit Do
        End If
        Prev = Now
        Ans = Ans + Now
        n = n + 1
    Loop
    Teylor = Ans
End Function