Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**juantheron****Member**- Registered: 2011-10-19
- Posts: 312

find no. of points (x,y,z) in space whose each coordinate is a Negative Integer such that x+y+z+12 =0

Offline

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

let x'= |x| , y'= |y| and z'= |z|

then we have x'+y'+z'=12

so x'<12 and y'<12 and z'<12

since you are looking for the number of this points i think i can assume you mean points with integer coordinates.

since 0<x',y',z'<12

we have that x',y',z' are in the set {1,2,3,4,5,6,7,8,9,10,11} which has 11 elements.

so x',y' and z' have 11 possibilities each,and so do x,y and z.

the number of such points is: 11*11*11=11^3=1331

*Last edited by anonimnystefy (2011-12-24 02:17:59)*

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.

Offline

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,481

Hi,

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Offline

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

hi gAr

oops! i think you're right.i forgot to take the condition x+y+z+12=0.i got the number of those which satisfy the equation x+y+z+12>0

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.

Offline

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

Merry Christmas and Happy Holiday, gAr and

anonimnystefy.

**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.**

Offline

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

it's not Christmas here yet.

we celebrate it on 7th of January.

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.

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,377

anonimnystefy wrote:

it's not Christmas here yet.

we celebrate it on 7th of January.

Wow, are you from Middle East?

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

Monox D. I-Fly wrote:

Wow, are you from Middle East?

I believe anonimnystefy is from Serbia. Orthodox Christians tend to celebrate Christmas on the 7th of January (as per the Julian calendar, which we don't use anymore -- we use the Gregorian calendar). Other countries do the same, like Russia.

**LearnMathsFree: Videos on various topics.New: Integration Problem | Adding FractionsPopular: Continued Fractions | Metric Spaces | Duality**

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,377

Isn't Serbia located in Middle East?

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,983

Hi Monox D. I-Fly,

Serbia, officially the Republic of Serbia, is a landlocked country situated at the crossroads of Central and Southeast Europe in the southern Pannonian Plain and the central Balkans. It borders Hungary to the north; Romania and Bulgaria to the east; Macedonia to the south; Croatia, Bosnia, Montenegro to the west and claims a border with Albania through the disputed territory of Kosovo. Serbia numbers around 7 million residents; its capital, Belgrade, ranks among the oldest and largest cities in Southeastern Europe.

*Located in the continent of Europe, Serbia covers 77,474 square kilometers of land, making it the 118th largest nation in terms of land area.*

*Serbia became an independent state in 1878, after gaining its sovereignty from Turkey. The population of Serbia is 7,276,604 (2012) and the nation has a density of 94 people per square kilometer.*

*The currency of Serbia is the Serbian Dinar (RSD). As well, the people of Serbia are refered to as Serbian.*

*The dialing code for the country is 381 and the top level internet domain for Serbian sites is .rs.*

*Serbia shares land borders with 8 countries: Macedonia, Albania, Bulgaria, Romania, Croatia, Bosnia and Herzegovina, Hungary, Montenegro.*

Source : https://www.worldatlas.com

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.

Offline

Pages: **1**