Which of the following represents the general term for the sequence 2, 4, 6, 8, 10, . . .?

n + 1
2n
2n - 1

Question

Which of the following represents the general term for the sequence 2, 4, 6, 8, 10, . . .?

n + 1
2n
2n - 1

xmoses1 · Answer

@AravindG This is it!

anonymous · Answer

well do it like this! 
n starts at 1 right?
n+1 = 2   @ n=1
good.
n+1 = 4   @n=2 
no good.

aravindg · Answer

First identify what type of sequence it is.

xmoses1 · Answer

It seems to be Arithmetic...

aravindg · Answer

Good.

Do you know general term for an Arithmetic sequence?

anonymous · Answer

2n = 2 @ n=1 
good.
 what about the rest of these numbers?

xmoses1 · Answer

Not off the top of head. I think it is something like $ {a_n} {(2^n +1)} =1 $ right? Or close to that

aravindg · Answer

$$a_n=a+(n-1)d$$

a=first term
d=common diff

aravindg · Answer

Substitute and be happy :)

xmoses1 · Answer

Ah I see! Thanks :)
Let me see... Then it would be 2n right?

aravindg · Answer

yes :)

xmoses1 · Answer

Thanks @AravindG :D

aravindg · Answer

yw :) But this is the general method. The answer could have been just got by looking at options too. Just applying common sense, 2n represents 2,4,6,8 etc.

xmoses1 · Answer

Yeah that is what i was having issues with lol. On the other ones i could do that, but this one i was getting very well. 

I am also going to choose not to take that as an insult to my common sense level xD

xmoses1 · Answer

*Was not