Question

Decide whether the formula an = –4n(n – 1) is explicit or recursive. Then find the first five terms of the sequence.

Answer 1

do you see if there is a common difference between terms?

Answer 2

does -7-(-5.6) = -4.2 - (-2.8) by chance?

Answer 3

if there is a common difference, then we can write up an arithmetic progression of the form:

an = a1+d(n-1)

Answer 4

or recuursively as:

an = a(n-1) + d