It is 'imperative' that the public be informed about these dangers. = It is 'imperative' to inform the public about these dangers.
“Go” and “buy” are 'imperatives' in the sentence “Please go to the store and buy some milk.”
She considers it a moral 'imperative' to help people in need.
(..) Oh, it's nothing. If you can prove you're not guilty, then I am in serious trouble. Because of the religious significance of the Pink Panther, it's imperative to the government that sooner or later... the thief be apprehended and the jewel returned. But you would prefer it to be later than sooner? (..)1975 The Return of the Pink Panther