A sequence has its first term equal to 4, and each term of the sequence is obtained by adding 2 to the previous term. If f(n) represents the nth term of the sequence, which of the following recursive functions best defines this sequence?

f(1) = 2 and f(n) = f(n − 1) + 4; n 1
f(1) = 4 and f(n) = f(n − 1) + 2n; n 1
f(1) = 2 and f(n) = f(n − 1) + 4n; n 1
f(1) = 4 and f(n) = f(n − 1) + 2; n 1

Question

A sequence has its first term equal to 4, and each term of the sequence is obtained by adding 2 to the previous term. If f(n) represents the nth term of the sequence, which of the following recursive functions best defines this sequence?

f(1) = 2 and f(n) = f(n − 1) + 4; n > 1
 f(1) = 4 and f(n) = f(n − 1) + 2n; n > 1
 f(1) = 2 and f(n) = f(n − 1) + 4n; n > 1
 f(1) = 4 and f(n) = f(n − 1) + 2; n > 1

Nevey · Answer

@Kamauri

Kamauri · Answer

We can describe the sequences two ways:
One:
T(1) = 4 and T(n+1) = T(n) + 2

Two:
T(n) = 2n + 2

You excluded the following so I did not know which is the correct version in this case (both convey the same point and mean the same thing)

Nevey · Answer

that explains nothing to me .-.

Kamauri · Answer

i know im sorry im stuck on this one

Nevey · Answer

its alright.

Nevey · Answer

@BenLindquist @Razor

dude · Answer

Arithmetic sequences are written as 
$a_n=a_1+(n-1)d$

$a_1$ is the first term
d is the "rate"