Which recursive formula can be used to generate the sequence below, where f(1) = 3 and n ≥ 1?

3, –6, 12, –24, 48, …

f (n + 1) = –3 f(n )

f (n + 1) = 3 f(n )

f (n + 1) = –2 f(n )

f (n + 1) = 2 f(n)

Question

Which recursive formula can be used to generate the sequence below, where f(1) = 3 and n ≥ 1?

3, –6, 12, –24, 48, …


f (n + 1) = –3 f(n )

f (n + 1) = 3 f(n )

f (n + 1) = –2 f(n )

f (n + 1) = 2 f(n)

danjs · Answer

do you notice the pattern in the numbers?

danjs · Answer

a consecutive term is double the last and oposite sign

danjs · Answer

the next term --- f( n + 1) 
is ---  =
-2 times previous term ---    -2 * f(n)

danjs · Answer

or since they gave you choices, you can just try each one out to see which works w/o knowing anything

danjs · Answer

the first term f(n) is 3   given to you, 

put that in each answer choice and see which gives back the next value in the sequence

anonymous · Answer

I got -6