nsider the following sequence. Sn(-1)(n+2) (a) Find the first three terms of the sequence whose nth term is given. S = 52 = S3 = (b) Classify the sequence as arithmetic, geometric, both, or neither. O arithmetic O geometric O both O neither If arithmetic, give d; if geometric, give r; if both, give d followed by r. (If both, enter your answers as a comma-separated list. If neither, ent