Question

The sequence is defined recursively. Write the first four terms.

a 1 = -10; a n = n - a n - 1

Answer 1

-10, 12, -9 and 13

Explanation:

Given the recursive sequence

a1 = -10

an = n - an-1

a2 = 2 - a1

a2 = 2 - (-10)

a2 = 2+10

a2 = 12

a3 = 3 - a2

a3 = 3 - (12)

a3 = -9

a4 = 4 - a3

a4 = 4 - (-9)

a4 = 4+9

a4 = 13

Hence the first 4 terms are -10, 12, -9 and 13