Question

find the first six terms of the sequences whose terms are an=(-1)^n/n ​

Answer 1

first term = 1 Consider, n = 1 (n + 1)^th term , i.e. (1 + 1)^th 2^ndterm = (1)^th term + (1 + 1) = 1 + 2 = 3. For n = 2, 3^rd term = 3 + 3 = 6 For n = 3, 4^th term = 6 + (3 + 1) = 10 Similarly, 5^th term = 10 + 5 = 15 & 6^th term = 15 + 6 = 21 & The sequence is 1,3,6,10,15,21 .