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Expressing 2*4*6*8*10*etc. mathematically

  • Thread starter Baou
  • Start date
  • #1
6
0

Homework Statement


This doesn't seem too hard but I can't figure it out. I'm trying to write out a power series expansion for a function, and after a bit of math I've got: [tex]f\left(x\right) = 1 - \frac32 + \frac98 - \frac{27}{48} + \frac{81}{384}... = 1 - \frac{3^1}2 + \frac{3^2}{2*4} - \frac{3^3}{2*4*6} + \frac{3^4}{2*4*6*8}...[/tex]


Homework Equations


N/A


The Attempt at a Solution


I just don't know how to express 2*4*6*8...etc. mathematically. Help please?
 

Answers and Replies

  • #2
gabbagabbahey
Homework Helper
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Hint: 2*4*6=23*1*2*3 :wink:
 
  • #3
6
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Damnit, I knew it'd be something simple... =P Well, thanks for the help!
 
  • #4
gabbagabbahey
Homework Helper
Gold Member
5,002
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I believe what you're looking for is...

[tex]\prod[/tex] 2x from 1 to infinity
Why would you think this?:confused:

[tex]\prod_{n=1}^{\infty} 2x=\infty[/tex]
 
  • #5
324
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Why would you think this?:confused:

[tex]\prod_{n=1}^{\infty} 2x=\infty[/tex]
Its late and I'm tired. Dont mind me.

I thought he was just asking how can you express 2*4*8... (I only read the title)
 

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