Public Sub Iteration()
    ' sng0 - начальное приближение.
    ' snqEps - требуемая точность.
    ' lngCount - количество итераций.
    Dim sng0 As Single
    Dim snqEps As Single
    Dim lngCount As Long
    Dim sngX As Single
    Dim sngY As Single
    
    sng0 =  1 
    snqEps =  0 . 01 
    
    sngX = sng0
    lngCount =  0 
    sngY =  0 . 4  + Atn(sngX ^  0 . 5 ) - sngX

    Do
        sngX = sngY
        sngY =  0 . 4  * sngX + Atn(sngX ^  0 . 5 ) - sngX
        lngCount = lngCount +  1 
    Loop Until Abs(sngY - sngX) < snqEps

    Debug.Print "Результат уравнения: " & sngY
    Debug.Print "Количество итераций: " & lngCount
End Sub