gspread documentation does not have any examples of adding formulas to the cells. If you try to use them with
update_cell methods it records them as a string and not as a Formula.
You should instead use the
Updating a Single Cell, considering you know the exact Row and Column Number
Updating a Single Cell, considering you the exact Row and Column Number are not known
cell = worksheet2.find("David Letterman")
row_number = cell.row