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Type I -- Infinite Summation


ballon

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If you have Ms. Word 2007, click menu Insert, add Equation (choose from the Built-in equations), scroll down, find Taylor Expansion there -- which is something similar to the picture below.

4f86329fe67a3e7238b31e2497d46ce1.png

Just ignore the sigma thing.. Now look at your Tn.

You see something similar? :ok:

If you are still in doubt I will give you further explanation :)

-You know the given sequence in Type I right? Do I have to calculate each one to get the answer of em and use those answers to put in the table? which will be used to obtain the sum of Sn?

(Were you able to understand what I've just said? XP )

-Do you think using the Infinite Geometric sequences formula to attain the sum of Sn from the given sequence is appropriate to use?

uhm, is this formula for the investigation to determine the sum of the infinite sequence tn?


Yessh so you should help me with TOK someday :) jk.. the numbers in the picture are for the first part in the task and they are the results from my formula :S just use exactly the same formulas and exactly the same CELLS because you don't know how to use Excel!! lol ;):D

in terms of the last response, I use the exact same methods as YOU did, but with MY own set of data? :P

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-You know the given sequence in Type I right? Do I have to calculate each one to get the answer of em and use those answers to put in the table? which will be used to obtain the sum of Sn?

(Were you able to understand what I've just said? XP )

-Do you think using the Infinite Geometric sequences formula to attain the sum of Sn from the given sequence is appropriate to use?

uhm, is this formula for the investigation to determine the sum of the infinite sequence tn?


in terms of the last response, I use the exact same methods as YOU did, but with MY own set of data? :D

- Doh...now if you use excel, you don't need to calculate each term of Tn or Sn BECAUSE excel will do it for you as you type the formulas that I gave you. so they will automatically give the numerical values of Tn and Sn. TRY FIRST!!! and then ask later if you face any problem

- of course not!! you cannot find Sn in this task using Infinite Geometric Sequences formula, no matter how hard you've tried

- the taylor expansion formula can be used to prove Sn, the infinite sum

- your own set of data? NO it's not possible because everybody in the world who is doing this task uses exactly the same data and will get the same answers. so yeah same method, and results will be the same.

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My teacher,apparently...Hmm...I haven't tamed my TI-89 that much yet, so, when I get to that stage I will come back to you to seek assistance on how to properly operate it if possible...

Thanks for your help.

By the way, is the sequence that is being used an Infinite Geometric Sequence? I just wanted to be sure...

Oh haha ok. Btw I thought it was the stellar numbers IA haha that's why I was like how the heck could you use excel for this?? lol I think Ms. Excel works best for this infinite summation IA.

How to Use Ms. Excel 2007 for Infinite Summation IA

  • Open your Ms. Excel 2007
  • In cell B2, put a
  • In cell C2, put x
  • In cell D2, put n
  • In cell E2, put Tn
  • In cell F2, put Sn
  • Merge cells B3 to B13 (Select these cells, On the Home tab, in the Alignment group, click Merge and Center)
  • Put the desired value of a in cell B3
  • Merge cells C3 to C13
  • Put the desired value of x in cell C3
  • Put 0 to 10 in cells D3 to D13 (values of n)
  • Type in the formula =(($C$3*LN($B$3))^D3)/FACT(D3) in cell E3
  • Copy that cell and paste in cells E4 to E13
    infinitesummationexcel.jpg
  • Type in the formula =SUM($E$3:E3) in cell F3
  • Copy that cell and paste in cells F4 to F13
    infinitesummationexcel2.jpg
  • Select cells E3 to F13
  • Right click, Format Cells, Number, Category: Number, Decimal Places: 6, OK
  • When you want to tabulate other values of a and x, I suggest starting a new worksheet so you can use exactly the same formulas for Tn and Sn (look at the image posted below); because starting a new table will change the formulas a little bit and it is going to be very confusing unless you have learned how to use Ms. Excel before.
    infinitesummationexcel3.jpg
  • You may want to take a screenshot and put it in Ms. Word so you do not need to calculate one by one the values of Tn and Sn. Do not forget to mention that you use Ms. Excel here.


And NO, it is NOT an Infinite Geometric Sequence. It is an infinite sequence, but it's not geometric.

Ok, so i've got the data down, how can i graph it? :D

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Ok, so i've got the data down, how can i graph it? :D

Mark...you are...technologically challenged -___- haha

The variables in which columns do you want to plot in excel? Let's say you want Sn against n. n is in column D and Sn is in column F. Click on those letters (your cursor will be an arrow faching downwards) while pressing Ctrl (I hope you use Windows too) and it will automatically select all values in that column. Then click menu Insert, Charts, Scatter, Scatter with only Markers.

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Ok, so i've got the data down, how can i graph it? :)

Mark...you are...technologically challenged -___- haha

The variables in which columns do you want to plot in excel? Let's say you want Sn against n. n is in column D and Sn is in column F. Click on those letters (your cursor will be an arrow faching downwards) while pressing Ctrl (I hope you use Windows too) and it will automatically select all values in that column. Then click menu Insert, Charts, Scatter, Scatter with only Markers.

LOL! T'was a joke XDD I got the graph!!! :ok: YESH! But...I got it wrong >_<

by the way, you know the Sn column? How were you able to obtain the data's there? I was able to obtain the Tn column successfully using the given sequences in the IA, should I also use those but with a different approach to it this time?

I do hope all our posts here will answer vast majorities for those people who will soon face this IA ;) So all they have to do is view OUR recent posts and problem solved. hahahaha :D

Edited by Austin Glau
no text speak
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LOL! T'was a joke XDD I got the graph!!! :S YESH! But...I got it wrong >_<

btw, you know the Sn column? How were you able to obtain the data's there? I was able to obtain the Tn column successfully using the given sequences in the IA, should I also use those but with a different approach to it this time?

I do hope all our posts here will answer vast majorities for those people who will soon face this IA :) So all they hafta do is view OUR recent posts and problem solved. hahahaha :)

Hahaha now have you got the correct graph? Tell me if you haven't.

Sorry I just woke up lol I'll be off to get ready for school in a few minutes. I will reply you again in about 12 hr :ok:

Meh.. the Sn column you just need to put in the formula that I wrote in the procedure. Please go back and check the procedure, read it step by step and see if you have done it exactly the way I told you to. Because when you are dealing with excel formulas it's hard to teach especially just on the net like this so yeah.. ;)

You found Tn using the given sequence? :) what do you mean? So you didn't use excel to calculate Tn?

Actually, use of technology is one criterion that is very easy to score. I am very sure that if you use excel formula to calculate Tn and Sn, you will definitely get full mark for this criterion; UNLESS you just calculate Tn and Sn using GDC and then just put the calculated values in the table. That makes the excel use just like using a normal table that you can draw in ms.word!

So yeah just follow those procedures I wrote yesterday. I think you also need to explain why you wrote those formulas in excel. I will explain it this evening, is that ok?

Yeahhh I hope they will read the whole thread of infinite summation very carefully so they won't ask the same questions over and over again :D

Btw do ask your classmates to join IBS! Especially if they are stuck in this IA :P

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Hahaha now have you got the correct graph? Tell me if you haven't.

Sorry I just woke up lol I'll be off to get ready for school in a few minutes. I will reply you again in about 12 hr :ok:

Meh.. the Sn column you just need to put in the formula that I wrote in the procedure. Please go back and check the procedure, read it step by step and see if you have done it exactly the way I told you to. Because when you are dealing with excel formulas it's hard to teach especially just on the net like this so yeah.. ;)

You found Tn using the given sequence? :S what do you mean? So you didn't use excel to calculate Tn?

Actually, use of technology is one criterion that is very easy to score. I am very sure that if you use excel formula to calculate Tn and Sn, you will definitely get full mark for this criterion; UNLESS you just calculate Tn and Sn using GDC and then just put the calculated values in the table. That makes the excel use just like using a normal table that you can draw in ms.word!

So yeah just follow those procedures I wrote yesterday. I think you also need to explain why you wrote those formulas in excel. I will explain it this evening, is that ok?

Yeahhh I hope they will read the whole thread of infinite summation very carefully so they won't ask the same questions over and over again :D

Btw do ask your classmates to join IBS! Especially if they are stuck in this IA :P

My teacher said I haven't. WHen i saw the other graph of one of the brightest dudes in the class, his was like diagonally increasing then curves to the right and stays like that throughout the graph. Whilst mine just goes up diagonally(the n-column) and there are two more lines which are my Sn and Tn - which I am presuming that it is the Sn that should go the way as my friends. But I am having tech. difficulties with it :) And y'know that column right? were most of them can be rounded of, excel is telling me that, but even if i do so, the graph doesn't change... :(

I used my GDC for Tn and Excel for Sn :S btw, Is it actually OK to use the term Tn for the first 3 questions of the IA? Because Tn doesn't come up until the last question...What does Tn mean,btw? HAHAHAHA

Suuuure :D Once it is half-term, i might as well pay you back :)

I've recommended this site to 3 of my friends already :) but, they don't use it as often as myself and Derek. :)

btw Desy my Sn bar, you know how your example is right? Mine just rounded itself to 1.999999. so yea.

Edited by Desy ♫
next time please use the EDIT button if you want to add something instead of multi-post-ing
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My teacher said I haven't. WHen i saw the other graph of one of the brightest dudes in the class, his was like diagonally increasing then curves to the right and stays like that throughout the graph. Whilst mine just goes up diagonally(the n-column) and there are two more lines which are my Sn and Tn - which I am presuming that it is the Sn that should go the way as my friends. But I am having tech. difficulties with it :S And y'know that column right? were most of them can be rounded of, excel is telling me that, but even if i do so, the graph doesn't change... :)

I used my GDC for Tn and Excel for Sn ;) btw, Is it actually OK to use the term Tn for the first 3 questions of the IA? Because Tn doesn't come up until the last question...What does Tn mean,btw? HAHAHAHA

Suuuure :) Once it is half-term, i might as well pay you back :ok:

I've recommended this site to 3 of my friends already :D but, they don't use it as often as myself and Derek. :P

btw Desy my Sn bar, you know how your example is right? Mine just rounded itself to 1.999999. so yea.

Well, what did you plot? Sn against n, right? I really can't help with technology because I cannot tell you what to do without seeing your desktop and clicking at stuffs!! It's really hard if you don't even know how to plot a graph on excel :D I suggest seeing an ICT teacher at school or just ask the IT guy in the computer lab at your school. Well, unless you can put the screenshot of your graph with the table here so I can make a rough guess of where your mistake is.

I suggest you not to do stuffs that I didn't mention in that procedure unless you are 100% sure that it is the right thing to do. Just follow the procedure strictly! Don't use GDC for Tn because it makes your Sn 1.999... instead of 2 because you are putting decimal numbers in Tn manually. If you use the formula I gave, as in you did it the way I did, your Tn will be exact numbers instead of the decimal numbers, and exact numbers are much more accurate thus it will make your Sn 2 instead of 1.999...!

Doh Mark :) Tn is defined in the very beginning of the task! Tn is your nth term! Tn and Sn are different. Can you tell me the difference now, to test your understanding?

Ok thanks, we'll see how. Help me with chem if you could thanks.

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okay so im just freaking out a bit

i know how to calculate everything, and ive done that , i just dont really know how to explain it. I dont know the terminology or anything... PLEASE HELP ME?!?!?

What do you want to explain? In which part? What exactly do you want to elaborate?

If you can give the rough explanation I can help rephrasing it and putting in mathematical terminologies to make it sound mathematical ;)

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What do you want to explain? In which part? What exactly do you want to elaborate?

If you can give the rough explanation I can help rephrasing it and putting in mathematical terminologies to make it sound mathematical ;)

well i mean in general..

i just dont really know what they want me to explain. do you know what I mean?

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well i mean in general..

i just dont really know what they want me to explain. do you know what I mean?

No :S;)

If you don't even know what you want to explain, how am I going to help you?

I don't think anything needs to be explained. Only a little bit perhaps. Maybe you need to explain why the Sn approaches a numerical value and that's it. You later need to explain how you arrive at the general statement too though :S

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No :S;)

If you don't even know what you want to explain, how am I going to help you?

I don't think anything needs to be explained. Only a little bit perhaps. Maybe you need to explain why the Sn approaches a numerical value and that's it. You later need to explain how you arrive at the general statement too though :S

okay well I cant just have the graphs and thats it,

all i want to know is what i need to explain

also i dont understand that everyone is saying a^x... because if a=2 and x=1 a^ would = 1. so how does that make sense.. could you explain that please?

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okay well I cant just have the graphs and thats it,

all i want to know is what i need to explain

also i dont understand that everyone is saying a^x... because if a=2 and x=1 a^ would = 1. so how does that make sense.. could you explain that please?

Haha right ;)

Then..explain the shape of the curve lah? lol divide it into sections first.. In the beginning how is it increasing? Very fast? As in, the gradient is steep or not? After that, is that still increasing? How fast? Is the gradient steeper or less steep? After that, is that still increasing? What value does Sn approach?

I cannot list what the things you need to explain are. Technically it's too much of a guidance and it's just like you are taking my ideas. You need to think critically, there are some things that I will not help with cuz if I do, it will limit your creativity and your mind :S

Yeah it's a^x. When x=1 you probably will not realise that yet but as soon as you investigate further you will then conclude that it's actually a^x :)

Btw when x=1 and a=2,

a^x=2

So that is correct :S

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okay well I cant just have the graphs and thats it,

all i want to know is what i need to explain

also i dont understand that everyone is saying a^x... because if a=2 and x=1 a^ would = 1. so how does that make sense.. could you explain that please?

Haha right ;)

Then..explain the shape of the curve lah? lol divide it into sections first.. In the beginning how is it increasing? Very fast? As in, the gradient is steep or not? After that, is that still increasing? How fast? Is the gradient steeper or less steep? After that, is that still increasing? What value does Sn approach?

I cannot list what the things you need to explain are. Technically it's too much of a guidance and it's just like you are taking my ideas. You need to think critically, there are some things that I will not help with cuz if I do, it will limit your creativity and your mind :)

Yeah it's a^x. When x=1 you probably will not realise that yet but as soon as you investigate further you will then canclude that it's actually a^x :)

Btw when x=1 and a=2,

a^x=2

So that is correct :S

hahah sorry! i meant it = 2... hahahaha

OH I GET IT NOW! im so sorry for bothering you :)

thank you so much! :S thank you thank you thank you!

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YO!!!!!! MINA!!! :) Can anyone tell me how should i "Describe what you notice from your plot. What does this suggest about the value of Sn as n approaches infinity?" and "Use your observations from these investigations to find a general statement that represents the infinite sum of this general sequence."

Arigato Gozaemasu Mina! :)

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thank you guys :)

YO!!!!!! MINA!!! :) Can anyone tell me how should i "Describe what you notice from your plot. What does this suggest about the value of Sn as n approaches infinity?" and "Use your observations from these investigations to find a general statement that represents the infinite sum of this general sequence."

Arigato Gozaemasu Mina! :)

Hmm you and mina (surviver?) are classmates..?

Yeah just describe the graph first. As I said:

divide it into sections first.. In the beginning how is it increasing? Very fast? As in, the gradient is steep or not? After that, is that still increasing? How fast? Is the gradient steeper or less steep? After that, is that still increasing?

What value does Sn approach?

And if n keeps increasing, what do you think will happen to the value of Sn? Will it keep increasing, stay constant or start decreasing?

Then yeah use that to get the S :D it's very simple and the answer can be found here if you read through the whole thread!

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thank you guys :S

Yeah just describe the graph first. As I said:

divide it into sections first.. In the beginning how is it increasing? Very fast? As in, the gradient is steep or not? After that, is that still increasing? How fast? Is the gradient steeper or less steep? After that, is that still increasing?

What value does Sn approach?

And if n keeps increasing, what do you think will happen to the value of Sn? Will it keep increasing, stay constant or start decreasing?

Then yeah use that to get the S :) it's very simple and the answer can be found here if you read through the whole thread!

erm, NO O_O Mina is everyone is japanese :) HAHAHAHA. :D

So, basically, from the looks of it, it's like describing a graph in chemistry then? :)

is it now? It's too troublesome since its all over the thread :)

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erm, NO O_O Mina is everyone is japanese :) HAHAHAHA. :)

So, basically, from the looks of it, it's like describing a graph in chemistry then? :D

is it now? It's too troublesome since its all over the thread :)

OHHH haha ok, that was an epic fail :S

Umm yes but you should put in some mathematical terminologies there :)

Yeah I know lol I happened to read the whole IA thread of my Type 1 IA because I didn't want to miss a single hint :) and it did help :)

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