Here is a tutorial to lock or hide only the formula cells in an Excel workbook. You can also lock formulas in all worksheets in a workbook.

First, select the cells with formulas you want to hide and protect, cells E4:E7 in our example sheet. Right-click the selection and choose Format Cells from the resulting submenu.

You can show or hide list of formulas while typing in Excel with the help of a shortcut key. Press Alt+Down arrow or make it invisible.

You can easily hide and unhide columns in Excel by individually revealing hidden columns or using the "Format" option to unhide all hidden cells.