For each set of conditions below, give an example of sequences/series that satisfy the conditions (and show that they do), or explain why the sequence/series cannot exist. (a) A sequence {a, } that is not monotonic, but converges to the limit 2021. (b) A series _ an that can be shown to converge using the Integral Test, but not the Ratio Test. (c) Two different series S an and by that converge to the same sum, and another series Cn n=1 n=1 n=1 that diverges, such that an