E.g.1 : Find the nth term of the sequence: 3, 7, 11, 15, ... The common difference is 4. Let N = an + b, where N is the nth term and a an b are constants to be found. 3 = a(1) + b = a + b 7 = a(2) + b = 2a + b Solving the two equations simultaneously, we get a = 4 and b = -1 So, the nth term, N = 4n - 1 …
