Question

Write a recursive definition for the following sequence.

2, -4, 8, -16

Answer 1

do you notice any patterns at all?

Answer 2

if not, then try thinking of each term as positive

2,4,8,16

what's the pattern here?

Answer 3

x -2?

Answer 4

times -2, yes

Answer 5

2 times -2 = -4
-4 times -2 = 8
etc etc

Answer 6

so the recursive rule is this

\[\Large a_{1} = 2\]
\[\Large a_{n} = -2*a_{n-1}\]

the first line above states the first term is 2. The next line tells you how to generate the other terms (multiply each by -2)

Answer 7

Thank you,

Answer 8

*!

Answer 9

you're welcome