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## Topic review (newest first)

ryos
2005-12-16 04:06:03

n is the number of iterations.

MathsIsFun
2005-12-15 22:52:44

It is "LaTeX" and I don't know it very well.

Just found this though

Ricky
2005-12-15 21:16:17

ryos, what's n?

And where can I look up commands for this code?

ryos
2005-12-15 18:30:48

I think this one is cleaner:

MathsIsFun
2005-12-15 17:52:46

Is this it?

#### Code:

$\sum_{k=1}^\infty2^{k+1}-2^{k-1}$
Ricky
2005-12-15 17:17:15

2^(k+1) - 2^(k-1)

K = 1:
2^2 - 2^0 = 4 - 1 = 3

K = 2:
2^3 - 2^1 = 8 - 2 = 6

K = 3:
2^4 - 2^2 = 16 - 4 = 12

K = 4:
2^5 - 2^3 = 32 - 8 = 24

And so on.

Alfred
2005-12-15 17:14:19

I couldn't get that to work out.  Are you sure?

Ricky
2005-12-15 17:10:07

Don't ask me how I got this, I couldn't tell you.  Just a bunch of guessing and checking:

Summation of k = 1 to n of 2^(k+1) - 2^(k-1)

Alfred
2005-12-15 17:06:00

I know all that, it's just this problem I can't get.

MajikWaffle
2005-12-15 16:57:30

n <- end of the sequence
Σ (Equation)
k = 1  <- starting

Alfred
2005-12-15 16:35:37

I'm new to sigma notation and I'm supposed to put 3 + 6+ 12+ 24 + 48 in it, but I really can't figure out how to do it.  I've tried for so long, but nothing I try works.  Can come help?