Табулирование функции от двух переменных в (VBA)

Sub Макрос1()
[C5] = 0.011
[C5].DataSeries Rowcol:=xlRows, Type:=xlLinear, Date:=xlDay, Step:=0.312, Stop:=0.874, Trend:=False
[B6] = 0.014
[B6].DataSeries Rowcol:=xlColumns, Type:=xlLinear, Date:=xlDay, Step:=0.001, Stop:=0.021, Trend:=False
[B5].Formula = "=ACOS((A1+B1)/D1)"
[B5].CurrentRegion.Table RowInput:=Range("A1"), ColumnInput:=Range("B1")
End Sub

Sub TabFunc()
    Dim a As Double, b As Double, c As Double, x As Double
    Dim i As Integer
    'On Error Resume Next
    Cells.Clear
    ' 0 <Arccos()<2pi
    ' Arccos(1)=0
    For a = 0.011 To 0.874 Step 0.312:    Next
    If a > 0.874 Then a = a - 0.312
    minX = a + 0.021
    x = InputBox("Ââåäèòå çíà÷åíèå X" & Chr(13) & " ìèíèìàëüíîå çíà÷åíèå Õ=" & minX)
    If x < minX Then Exit Sub
    i = 3
    Cells(1, 1) = "X = " & x
    Cells(2, 1) = "a"
    Cells(2, 2) = "b"
    Cells(2, 3) = "c"
    For a = 0.011 To 0.874 Step 0.312
        For b = 0.014 To 0.021 Step 0.001
            Cells(i, 1) = a
            Cells(i, 2) = b
            c = WorksheetFunction.Acos((a + b) / x)
            Cells(i, 3) = c
            i = i + 1
        Next
    Next
End Sub