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Math help =)

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Old Mar 26, 2011 | 02:07 AM
  #11  
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The summation is finite - all alternating series where the terms approach zero converge
Not true. Consider the alternating series,

1-1/3+1/2-1/3[sup]2[/sup]+1/3-1/3[sup]3[/sup]+1/4-1/3[sup]4[/sup]+1/5-1/3[sup]5[/sup]+............

diverges but terms approach zero.

The correct statement is "all alternating series where the terms approach zero and absolute values of the terms decrease converge"

Gaja
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Old Mar 26, 2011 | 09:37 AM
  #12  
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Originally Posted by gaus
The summation is finite - all alternating series where the terms approach zero converge
Not true. Consider the alternating series,

1-1/3+1/2-1/3[sup]2[/sup]+1/3-1/3[sup]3[/sup]+1/4-1/3[sup]4[/sup]+1/5-1/3[sup]5[/sup]+............

diverges but terms approach zero.

The correct statement is "all alternating series where the terms approach zero and absolute values of the terms decrease converge"

Gaja
Good point. Althouth it should read, ". . . absolute values of the terms eventually decrease . . ."; what happens with the first n terms (n any whole number) is irrelevant.
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Old Mar 26, 2011 | 09:42 AM
  #13  
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Originally Posted by gaus
The infinite sum is equal to e[sup](-1/2)[/sup].
Yes beta ultimately cancels out.
Gaja
Again, good point.

I haven't looked at infinite series for a while; now that you mention the sum, it's obvious.
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Old Mar 26, 2011 | 01:07 PM
  #14  
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If the infinite sum is equal to e^(-1/2)

Then we have
{e^(-1/2)^4B}
which = e^(-2B)

collecting like terms we have
e^0
which = 1

Which leaves me with
[{alpha^2/(alpha*beta^2)} + 1]

I'm so lost... how did you get rid of the alphas and betas???
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Old Mar 26, 2011 | 04:52 PM
  #15  
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Originally Posted by ******e
If the infinite sum is equal to e^(-1/2)

Then we have
{e^(-1/2)^4B}
which = e^(-2B)

collecting like terms we have
e^0
which = 1

Which leaves me with
[{alpha^2/(alpha*beta^2)} + 1]

I'm so lost... how did you get rid of the alphas and betas???
I don't see any alpha in the original. Where'd you get them?
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Old Mar 26, 2011 | 05:27 PM
  #16  
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Looks like greek alphabets aren't my forte either lol. What does that symbol that looks like a mirrored "6" represent then? Is it just a variable?
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Old Mar 26, 2011 | 05:42 PM
  #17  
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Originally Posted by ******e
Looks like greek alphabets aren't my forte either lol. What does that symbol that looks like a mirrored "6" represent then? Is it just a variable?
It designates a partial derivative: for a function of more than one variable it is the derivative with respect to one of the variables, treating the other variables as constants.

It's out of place here because the function e[sup]53β[/sup] has only one variable: β; it would be more appropriate to have d[sup]2[/sup]/dβ[sup]2[/sup]: the second derivative with respect to β.
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Old Mar 26, 2011 | 11:17 PM
  #18  
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thanks magician =)
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Old Mar 27, 2011 | 12:14 AM
  #19  
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So my final answer is 416 - [625 - 37] - [2810]
= 416 - 588 - 2810
= -2982


does that look right?
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Old Mar 27, 2011 | 10:00 AM
  #20  
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Originally Posted by ******e
thanks magician =)
My pleasure.
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