You can always go back and view or edit a formula that has been added to a search. Do this by clicking the edit icon next to its name in the Columns listing.
Anyone who has edit privileges on an answer can also edit any formulas it contains. To view or edit an existing formula in an answer:
1. Navigate to the pinboard that contains the answer with the formula, and open it.
2. Scroll down to the bottom of the Columns listing. You will see a data source called Formulas.
3. Expand Formulas, and you'll see a list of all the formulas in this answer.
4. Click the edit icon next to the formula name.
5. Type your formula in the Formula Builder.
Note: Formulas elements are color coded by type and can include the formula operators and functions (blue), the names of columns (purple), and/or constants (black).
6. Click Save to save the formula with your changes.