Question

I've learned this before .. i just need a recap or review to make sure i'm remembering it right.

Find the first six terms of the sequence.

a1 = 6, an = 2 • an-1

Answer 1

a1 = 6, an = 2 • an-1

6, 12, 14, 16, 18, 20
12, 24, 48, 96, 192, 384
0, 2, 12, 14, 16, 18
6, 12, 24, 48, 96, 192

Answer 2

Well:
\[
\begin{align}
a_1 &= 6\\
a_n &= 2a_{n-1}
\end{align}
\]

So:
\[
\begin{align}
a_2 &= 2a_1 = 2 \cdot 6 = 12\\
a_3 &= 2a_2 = 2 \cdot 12 = 24
\end{align}
\]

And so on.

Answer 3

Yeah alright see i got up to the second part and was doing 2*6 ... but now that you said that i remember learning it that way .. thank you so much .. mind helping with another ?

Answer 4

Sure. Fire away.

Answer 5

Find an equation for the nth term of the arithmetic sequence.

-17, -12, -7, -2, ...

an = -17 + 5(n + 2)
an = -17 + 5(n + 1)
an = -17 + 5(n - 1)
an = -17 x 5(n - 1)

Answer 6

i think its B ?

Answer 7

i could be completely wrong .. i know for sure its not D

Answer 8

Either B or C ?

Answer 9

As far as I can tell, neither. I think it should be:
\[
a_n = -17 + 5n
\]

Answer 10

hmm thats strange .. ill go with b just because thats what popped out at me .. mind helping with 1 more ? sorry lol

Answer 11

Find the first six terms of the sequence.

a1 = -4, an = an-1 + 7

-4, 3, 10, 17, 24, 31
-4, 7, 14, 21, 28, 35
3, 10, 17, 24, 31, 38
0, 7, 14, 21, 28, 35

I think its A ?

Answer 12

It has to be A or B, and since the second element should be 3, it's A. Remember: it's just algebra. a1 is a variable just like x is, and a2 is just something plus a1. a3 is just something plus a2, and so on.