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Type I -- Stellar Number


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Hey guys, this is my first post.

I got the Stellar Numbers IA the other day and I'm having some trouble with finding the equation for 6-point stellar numbers.

Could someone please help me find the equation? I don't need to know the equation (it would help though), I need some help with the process.

Thanks!

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Hey guys, this is my first post.

I got the Stellar Numbers IA the other day and I'm having some trouble with finding the equation for 6-point stellar numbers.

Could someone please help me find the equation? I don't need to know the equation (it would help though), I need some help with the process.

Thanks!

There are many different ways to get it. I suggest paying attention at the difference between each term and expressing Sn in such a way to make the differences clear.

However if you are really really stuck, just plot Sn against n and get the quadratic best fit haha

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Hi, fellow IBers. I have found all the equations and even discovered a way to prove them geometrically, which was surprise for myself, since I've never been good at such stuff. Anyway, now I am confused about what to write in Intro. Any suggestions? Do I simply have to write what triangular and stellar numbers are and what I am going to do with them?

Thanks in advance

Elīna

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Hi, fellow IBers. I have found all the equations and even discovered a way to prove them geometrically, which was surprise for myself, since I've never been good at such stuff. Anyway, now I am confused about what to write in Intro. Any suggestions? Do I simply have to write what triangular and stellar numbers are and what I am going to do with them?

Thanks in advance

Elīna

Great! Congrats! :P :P

Oh people always don't know how to write an intro :lc: referring back to this guide,

Introduction

• Define some terms where appropriate (i.e. define Triangular and Stellar Numbers). If you do not come up with the definitions by yourself, citations should be included as footnotes.

• Introduce the problem in the task (i.e. special numbers)

• Briefly describe what your portfolio is all about (finding the general formula of each term of the special numbers)

• Mention the purpose of the portfolio (similar with above actually :hmmm:)

• Name the software or program(s) that you are going to use

• Include a logo of all the software or program(s) used

Good luck!

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Whats the general formula? right at the beginning, like Find a general statement that represents the nth triangular number in terms of n

can someone explain me how to get there? :)

For the triangular number..look at the pattern, the difference between each terms. There are many methods to get there but the easiest way (yet I consider not-so-mathematical) is to plot Sn against n and get the best fit.

The mathematical way is to algebraically find the formula :) the only hint is to look at the difference :D

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Hey peeps.

Alrighty so I repeated the steps for the other p values and now I have to produce a general statement using p and n...

I came up with one but I'm not sure if it works and also how I would explain it.

General Statement: Sn=pn^2+pn+1

Any help would be greatly appreciated. Thank you. :)

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Hey peeps.

Alrighty so I repeated the steps for the other p values and now I have to produce a general statement using p and n...

I came up with one but I'm not sure if it works and also how I would explain it.

General Statement: Sn=pn^2+pn+1

Any help would be greatly appreciated. Thank you. :D

It's correct, but how did you come up with it if you don't know how to explain it in the first place? :)

I suggest putting a table of values of p and the general formula Sn (in terms of n). I think the pattern would be very obvious. Since Sn is in the form of Sn=an²+bn+c, you may want to talk about the a first and then b and then c :D and you are done with this part! :)

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Hey peeps.

Alrighty so I repeated the steps for the other p values and now I have to produce a general statement using p and n...

I came up with one but I'm not sure if it works and also how I would explain it.

General Statement: Sn=pn^2+pn+1

Any help would be greatly appreciated. Thank you. :D

It's correct, but how did you come up with it if you don't know how to explain it in the first place? :)

I suggest putting a table of values of p and the general formula Sn (in terms of n). I think the pattern would be very obvious. Since Sn is in the form of Sn=an²+bn+c, you may want to talk about the a first and then b and then c :D and you are done with this part! :)

Hmm okie dokie. Thank you. I used my GDC to come up with a, b, c so I guess I'll just explain that. And then I do what you suggest and create a table for values of p and the general formula. :D

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Hi guys :)

I'm doing this IA now and I've just found a great way to figure out some of the things in the internal. It's to use your calculator (TI-84 for me).

-Use the Stat> 1:Edit and

-Put in the values.L1 is the term number (eg.1, 2, 3, 4, etc...) and L2 is the number of dots in the star.

-Then use Stat>Calc>5:QuadReg>2nd Stat> L1, comma, L2.

-Enter

-You then get values for a quadratic expression, which is only for a specific value of p.

Repeat this method with different values of p (eg. a three pointed or an eight pointed star) and you should get an expression.

The same method can be used to find the general statement for the triangles.

As for drawing the stars (triangles are pretty simple), search for an outline of the type of star you want (eg. 3 points, 7 points) or draw one yourself on paint. Then insert the dots in place! Copy the 'main' star and resize it to create larger stars. Dont forget to add the extra dots.Also, from what I know, Windows Word already has a four pointed and a 5 pointed star

If you're really a perfectionist, use Photoshop if you have it to create the stars, because you're able to have a lot more control on the images (the stars).

Hope this helps! :D

btw, if my instructions are confusing, let me know. I'll try and put up a screenshot of what I mean :)

Edited by dftba
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I have been assigned stellar numbers portfolio for this year, which is due in two-three weeks. I have been working on it for a while, and I have figure most of it out. The only thing I'm stumped on is the star numbers formula relating to terms of n. I have got the formula which works but I have no idea what to do to get the formula. Any help given would be appreciated.

Think about it. Your term number is n, right? and your dot number is considered tn

If you've done all the questions the paper lists, it says you have to solve for other values of p, they do this in order for you to NOTICE that that P= a,b, because your equation is a quadratic. (tn= a(n2)+b(n)+ c

because your value of p is the number of point, but it corresponds to the a and b values of a quadractic.

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Okay, it's my very first post here so please be understanding :)

I'm doing my portfolio on stellar numbers right now and i'm just wondering whether I'm on the right track. I arrived at the conclusion that the formula for the shapes with 6 vertices would be 6n2-6n+1 but I'm not sure if I'm supposed to expand it or sth?

Also, can I use any value of p in my further calculations (I was thinking about one even and one odd number - are two numbers enough?)

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Okay, it's my very first post here so please be understanding :)

I'm doing my portfolio on stellar numbers right now and i'm just wondering whether I'm on the right track. I arrived at the conclusion that the formula for the shapes with 6 vertices would be 6n2-6n+1 but I'm not sure if I'm supposed to expand it or sth?

Also, can I use any value of p in my further calculations (I was thinking about one even and one odd number - are two numbers enough?)

Welcome to IBS :)

Yup that is correct.. No need to express it in any other form..

I suggest having 3 or 4 more values of p :/ I am not sure with the variation but just make it 'various' you know. You may want to try greater numbers too :)

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Welcome to IBS :)

Yup that is correct.. No need to express it in any other form..

I suggest having 3 or 4 more values of p :/ I am not sure with the variation but just make it 'various' you know. You may want to try greater numbers too :)

Thanks :)

And another question, should I draw every single diagram for other values of p?

Also, do you recommend any programms for drawing them?

Edited by Desy ♫
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Thanks :)

And another question, should I draw every single diagram for other values of p?

Also, do you recommend any programms for drawing them?

No problem.

I don't think the paper asks you to put the diagrams but if I were you I would just draw it to get the number of dots in each star.

I don't recommend drawing them by yourself but if you can, go for it. I believe there is a site that provides you the graphs. The link is somewhere in this thread, just go through this thread to find it. Don't forget to cite if you use those :)

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Hey im new here :) and i just got my maths portfolio on stellar numbers and its due in a week.. i really dont know how to start it..do i write up an introduction? or just start solving the paper straight away?

Help will very much be appreciated :)

Thanks :)

Diana

intro first :)

a suggested outline can be found here:

http://www.ibsurvival.com/topic/8208-portfolio-type-i-stellar-numbers/page__view__findpost__p__101100

a more detailed and general format of a Math IA can be found here:

http://www.ibsurvival.com/topic/12330-mathematics-portfolio-tips-for-hl-and-sl/

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Aaww thank you so much! :) That's really going to help me! :)

I hope I'm not asking for too much but there's this question, 'produce the general statement in terms of p and n, that generates the sequence of p-stellar numbers for any value of p at stage Sn'

I don't get it..are we like..supposed to join the two formulas or?

Edited by Diana Winchester
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