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#1 2013-05-22 06:14:05

BarandaMan
Guest

Rearranging Urgent Help!! Part 2

Hi there!

This step in the textbook has had me stumped smile

tinypic.com/r/24359up/5

So there is one term on the RHS which clearly makes a lot of sense, but then somehow, there is a Pi* and (Pi - Pi*) term, broken down from the initial term. We require it in this format to show inflation bias, just incase you are interested. But I cannot seem to find a way to make it like that.

Please help big_smile:D

#2 2013-05-22 06:23:23

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 96,661

Re: Rearranging Urgent Help!! Part 2

Hi;

That is correct, what have you tried?


In mathematics, you don't understand things. You just get used to them.

If it ain't broke, fix it until it is.

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#3 2013-05-22 06:46:26

BarandaMan
Guest

Re: Rearranging Urgent Help!! Part 2

bobbym wrote:

Hi;

That is correct, what have you tried?

You did it that quickly? Oh my....

I have tried expanding the RHS, splitting them up into three terms each with the same denominator. I worked backwards (cheated) from the answer to try and saw that:

aPi*=Pi*(a+b^2-b^2) = Pi*(1 - (b^2)/a+b^2) = Pi* - (Pi*b^2/a+b^2) which is the term, but I do not know how I would have got there without the answer to go back from. Does this make sense? big_smile

#4 2013-05-22 06:56:34

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 96,661

Re: Rearranging Urgent Help!! Part 2

Hi;

I am working on it, so far I am not getting it either.


In mathematics, you don't understand things. You just get used to them.

If it ain't broke, fix it until it is.

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#5 2013-05-22 07:10:31

BarandaMan
Guest

Re: Rearranging Urgent Help!! Part 2

bobbym wrote:

Hi;

I am working on it, so far I am not getting it either.

Ok thank you. Don't spend too long on it if it is too much hassle, I do not mind going backwards in the exam big_smile

#6 2013-05-22 07:23:20

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 96,661

Re: Rearranging Urgent Help!! Part 2

Hi;

The only thing I can think of is he used this identity here.

Why he wanted to? I do not know.


In mathematics, you don't understand things. You just get used to them.

If it ain't broke, fix it until it is.

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#7 2013-05-22 07:29:28

BarandaMan
Guest

Re: Rearranging Urgent Help!! Part 2

Oh my, but this identity works with this example completely? I think I should study all of the identities.... you are incredible, again, bobby! tongue
Haha big_smile (and still a genius...)

#8 2013-05-22 07:34:25

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 96,661

Re: Rearranging Urgent Help!! Part 2

Him using that identity is very weird. I have no idea why he wanted to get the

together. The original equation was fine.


In mathematics, you don't understand things. You just get used to them.

If it ain't broke, fix it until it is.

Offline

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