Math Is Fun Forum

barandaman

Guest

Rearranging Urgent Help!! Part 3, last one I promise!

tinypic.com/r/2u6gyef/5

Hi,
Could someone please help me with this problem?
I have done some of the deriving up to this point, so if we cannot move from the LHS to the RHS on the attached image, I have done something wrong up to this point and then I will take another photo to show the previous steps, but I really think they were right as it was much more simple.
So we have to get from the LHS to the RHS, dividing by ‘a’ gives the first two terms, but then I really do not understand how the LAST term on the RHS becomes ‘b/a’. Could anyone shed some insight? Thank you so much! Image attached.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Rearranging Urgent Help!! Part 3, last one I promise!

Hi barandaman;

What have you done so far?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

barandaman

Guest

Re: Rearranging Urgent Help!! Part 3, last one I promise!

I will write it out neatly and take a photo because I have not learnt latex 5 minutes!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Rearranging Urgent Help!! Part 3, last one I promise!

Hi;

See if you can write the problem out larger too.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,646

Re: Rearranging Urgent Help!! Part 3, last one I promise!

hi barandaman

here's the LHS using Latex.

I think you need to do two things.

(i)  tell us what the question asks

(ii) show how you got this far.

Please use Latex:

You start with square brackets math and end with square brackets /math

The code for the above is:

There is a code for the line over the y but I forget at the moment.  But ybar is clear I think.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Bob

Administrator

Registered: 2010-06-20

Posts: 10,646

Re: Rearranging Urgent Help!! Part 3, last one I promise!

hi bobbym,

Didn't see your post as I was taking a long time over mine. 

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

barandaman

Guest

Re: Rearranging Urgent Help!! Part 3, last one I promise!

tinypic.com/r/rgxlwy/5

It is the problem we looked at yesterday, to solve it we set PI=PI^e, so all that changes is the LHS term is PI^e.

Then I expand the RHS as seen, and get the result as shown initially in the first image. I have no idea how to convert that into the solution, which is:

Pi^e = Pi^* + (b/a)(y^* - ybar)

I hope this is clearer!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Rearranging Urgent Help!! Part 3, last one I promise!

Hi bob bundy;

That is okay.

Use

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,646

Re: Rearranging Urgent Help!! Part 3, last one I promise!

hi barandaman

That last line is not quite correct.

Your pi terms have lost their denominator.

Put that in and you can cancel it throughout.  The expression is then much simpler.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

barandaman

Guest

Re: Rearranging Urgent Help!! Part 3, last one I promise!

hi barandaman

That last line is not quite correct.

Your pi terms have lost their denominator.

Put that in and you can cancel it throughout.  The expression is then much simpler.

Bob

I really am having trouble with the latex...

The pi terms are different, one is pi^e one is pi^*

barandaman

Guest

Re: Rearranging Urgent Help!! Part 3, last one I promise!

GOT IT! tghank you so much now i know what you mean, ahhhh thank you