The correct options are
A 0, 12, 1, 32, 2
C −√2, 0, √2, 2√2, 3√2
(a) We have a2−a1 = (12) − 0 = 12 a3 − a2 = 1− (12) = 12 a4 − a3 = (32)− 1 = 12 i.e., an− an−1 is the same everywhere.So, the given list of numbers form an AP.
(b) We have a2−a1 = 4 − 1 = 3 a3 − a2 = 9− 4 = 5 a4 − a3 = 16− 9 = 7 i.e., an− an−1 is not the same everywhere. So, the given list of numbers do not form an AP.
(c) We have a2−a1 = 0 − (−√2) = √2 a3 − a2 = √2− 0 = √2 a4 − a3 = 2 √2− √2 = √2i.e., an− an−1 is the same everywhere. So, the given list of numbers form an AP.
(d) We have a2−a1 = 10 − 5 = 5 a3 − a2 = 20− 10 =10 a4 − a3 = 35−20 = 15i.e., an− an−1 is not the same everywhere. So, the given list of numbers do not form an AP.