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**Amartyanil****Member**- From: Universe
- Registered: 2013-05-27
- Posts: 81

Hi;

All things on a planet or a sattelite, that we see straight are actually curved and the things that we see curved are actually straight!

"Every place is the center of the universe. And every moment is the most important moment. And everything is the meaning of life." ~ Dan Harmon

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Explain...

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**Amartyanil****Member**- From: Universe
- Registered: 2013-05-27
- Posts: 81

The theory of curveness is true because any planet, satellite or star are always spherical in shape.

Things on a planet, satellite or a star that we see straight are actually curved because when we come beyond the planet, we see the thing curved. E.g., the great wall is straight on it upper or the lower surface, beyond it's planet we see that the great wall is curved.

"Things on a planet, satellite or a star that we see curved are actually straight", this theory is right or wrong, I cannot prove it.

"Every place is the center of the universe. And every moment is the most important moment. And everything is the meaning of life." ~ Dan Harmon

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Well, nothing is exactly straight. Do you have some kind of a definition of a real world straight line?

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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Definition: A figure is said to be straight (in a three dimensional space) if the two endpoints of the figure are at minimal distance.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

Minimal as compared to?

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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It is the least possible distance and only one such configuration exists.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

The "least possible distance" depends on the metric used. Each space has it's own metric.

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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What is a metric?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

It's a function that assigns values to distances. It also has to satisfy a few properties, but those are not important for what we're discussing.

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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In the 3D space, I can only concieve of one kind of distance. Please explain if there exists others

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,039

The one you are thinking of is called the Euclidian distance. There exist others. There is quite a bit on this on the net.

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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With what keyword should I search for?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

http://en.wikipedia.org/wiki/Metric_%28mathematics%29

The term is used a lot in vector analysis and differential geometry.

**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.**

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**Amartyanil****Member**- From: Universe
- Registered: 2013-05-27
- Posts: 81

Amartyanil wrote:

Hi;

All things on a planet or a sattelite, that we see straight are actually curved and the things that we see curved are actually straight!

I have corrected it:

All things on any spherical celestial bodies that we see straight are curved and I am not sure about curved things.

"Every place is the center of the universe. And every moment is the most important moment. And everything is the meaning of life." ~ Dan Harmon

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Two things are infinite, stupidity and the universe... I am not sure about the universe.

-Einstein

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Abraham Pais wrote:

Einstein, this little man...

**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.**

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**Shachile****Member**- Registered: 2019-11-21
- Posts: 2

Help me to proofs the identity[A,B + C]= [A,B] + [A, C]

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**bob bundy****Administrator**- Registered: 2010-06-20
- Posts: 8,711

hi Shachile

Welcome to the forum.

I think your notation is + = AND , = OR

Sorry if I've misunderstood.

To prove this I'd really need to see how these were defined in your course, but the following may help you to construct a suitable proof:

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 Bundy

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**Shachile****Member**- Registered: 2019-11-21
- Posts: 2

I think this maybe of help

[A,B]=AB-BA= - [B,A]

[A,BC]=[A,B]C+B[A,C]

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