7. (a) Determine whether the sequence 9 - 4n3 arctan 2n2 n=1 DNE. is convergent. If the sequence is convergent, find its limit. If the sequence does not converge, write(b) Determine whether the series en is convergent. Note that the summation begins at n = 1 (not n = 1 n = 0). If the series is convergent, find the sum. If the series does not converge, write DNE