Is there a line of code that will hide all cell formulae/ functions?

Is there a way to adjust the following code to apply to only cells populated
with formulae/ functions?

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Formula < dtval Then Target.Formula = dtval
End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
dtval = Target.Formula
End Sub

'From
'http://www.dotxls.com/excel-security/27/how-to-protect-an-excel-sheet-with-vba-macro-code