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## #1 2012-10-29 11:28:39

MathsIsFun
Registered: 2005-01-21
Posts: 7,619

### Quadratic Equations in the Real World

How is it?

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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## #2 2012-10-29 11:40:00

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,015

### Re: Quadratic Equations in the Real World

Hi MIF

I love it. It has many methods for solving quadratics and applied to real world examples.

Btw, the -9.3 next to the graph for the steel frame problem split into to lines so it looks like the solutions are 9.3 and 0.8. Also, some fractions down at the resistor problem look rather odd...

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #3 2012-10-29 11:42:22

bobbym
From: Bumpkinland
Registered: 2009-04-12
Posts: 104,724

### Re: Quadratic Equations in the Real World

Hi MIF;

A lot to cover there but very well done.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.

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## #4 2012-10-29 20:00:55

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,613

### Re: Quadratic Equations in the Real World

hi MathsIsFun,

Another excellent page.  I hadn't looked at the quadratic solver and grapher before but this page led me to them.  I just love these interactive features.

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

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## #5 2012-10-29 21:11:06

ganesh
Moderator
Registered: 2005-06-28
Posts: 21,060

### Re: Quadratic Equations in the Real World

Hi MathsIsFun,

Excellent page. Loved it. Thanks!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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## #6 2012-10-29 22:24:56

MathsIsFun
Registered: 2005-01-21
Posts: 7,619

### Re: Quadratic Equations in the Real World

Thanks guys

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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## #7 2012-11-04 19:33:16

Calligar
Member
Registered: 2011-09-24
Posts: 272

### Re: Quadratic Equations in the Real World

Sorry, I'm actually quite tired, but I kind of forced myself to read through the whole thing.  At first I was confused because for some odd reason, I was thinking the whole thing was talking about matrices (I honestly have no idea why I was thinking that); but after figuring it out, I find this thing quite interesting.  I don't know if I have ever really tried applying quadratic equations to the real world like that, but now I see it done and was like, well, I'm not quite sure how else to put it, interesting.  I'm sure others will find this useful.

There are always other variables.  -[unknown]
But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end.  -Aristotle
Everything makes sense, one only needs to figure out how.  -[unknown]

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## #8 2012-11-05 01:44:27

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,015

### Re: Quadratic Equations in the Real World

anonimnystefy wrote:

Hi MIF

I love it. It has many methods for solving quadratics and applied to real world examples.

Btw, the -9.3 next to the graph for the steel frame problem split into to lines so it looks like the solutions are 9.3 and 0.8. Also, some fractions down at the resistor problem look rather odd...

Good thing that nobody read this!

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #9 2012-11-05 03:34:05

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,613

### Re: Quadratic Equations in the Real World

I did.  Didn't want to admit I hadn't a clue what you meant.  Still don't.

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

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## #10 2012-11-05 03:37:30

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,015

### Re: Quadratic Equations in the Real World

Look at the graph for the steel frame problem. In the text next to it, the "-9.3" split into two lines so it looks like:
"blahblah, something -
9.3 blahblah something"
It might be mistaken for 9.3 which is not a solution...

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #11 2012-11-05 03:45:21

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,613

### Re: Quadratic Equations in the Real World

MIF must have changed it as it is OK now.

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

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## #12 2012-11-05 03:49:33

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,015

### Re: Quadratic Equations in the Real World

When I opened it today it was still the same... Sorry about that then.

But there are still the fractions at the resistor problem which look a little odd to me. How do they look to you? My phone might have a strange formatting that causes that...

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #13 2012-11-05 05:10:39

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,613

### Re: Quadratic Equations in the Real World

It all looks ok with IE9.  Gosh that's a first Mr G !

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

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## #14 2012-11-05 19:08:05

Calligar
Member
Registered: 2011-09-24
Posts: 272

### Re: Quadratic Equations in the Real World

Yeah, I don't remember seeing that either the page either, but if it's changed now, that might have been why.  If not, it was probably because I was really tired yesterday.  I had read what you wrote, but I didn't personally notice it...

There are always other variables.  -[unknown]
But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end.  -Aristotle
Everything makes sense, one only needs to figure out how.  -[unknown]

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