Trendline problems

[loro]

Hello!

I'm not well versed at spreadsheets, so please excuse me if these are stupid questions.

1. If I delete a trendline its legend is till there. How do I get rid of it?

2. The trendline doesn't seem to update as I add new data to the table. What do I need to do to make that happen?

[robert-l]

1. Mark (click on) the legend of the deleted trendline and delete the legend.
2. A trend line usually does not update extremely and it is possible that even several changes do not produce a visible result.