one For each of the following statements write "true" if the statement is correct or "false" otherwise. 1. A sequence {a} is a function whose domain is the set of integers or a subset of consecutive integers starting with 0 2. An arithmetic progression (4) with the first term A, and the common difference d, then the nth term is given by: An = A1+(n-1)d. 3. Let {an} be a sequence and MER. Then M is said to be an upper bound of (an), if Mza, for all a, e { an}. 4. A sequence {an) is said to be a null sequence, if and only if lima, = 1. ​