It says in the article that :
"Transaction log backups – makes a copy of all the log records inserted into the transaction log since the last transaction log backup (or database checkpoint, if working in SIMPLE recovery mode)."
as long as I know, there is no way to take transactional backup from a Database with simple recovery model.
although, it said in the beginning of the paragraph, that it's not applied when in simple recovery model,
is there a point to mentioning this afterward ?