bomaha Posted November 8, 2011 Report Share Posted November 8, 2011 So the one question I have is about the infinity. Do you think they want us to do just positive infinity, or should we do decimal infinity as well? Such as when we're testing the validity of our general statement.only positive@ desy: positive decimals, integers, etc should work too. Reply Link to post Share on other sites More sharing options...
bomaha Posted November 8, 2011 Report Share Posted November 8, 2011 This is my teacher comments on this portfolio:It is so far beyond the SL syllabus that students will not be able to do much in the way of justification, formal or informal. For SL, this task should have stopped after the first page. Reply Link to post Share on other sites More sharing options...
dessskris Posted November 8, 2011 Report Share Posted November 8, 2011 So the one question I have is about the infinity. Do you think they want us to do just positive infinity, or should we do decimal infinity as well? Such as when we're testing the validity of our general statement.only positive@ desy: positive decimals, integers, etc should work too.she was asking positive and negative infinity or positive only, i meant to say there's no need to consider negative infinity. of course values other than that need to be taken into account too. Reply Link to post Share on other sites More sharing options...
dessskris Posted November 8, 2011 Report Share Posted November 8, 2011 This is my teacher comments on this portfolio:It is so far beyond the SL syllabus that students will not be able to do much in the way of justification, formal or informal. For SL, this task should have stopped after the first page.I personally think it's still possible since it's just using calculator to count the sums and the general formula is very simple anyway (if you compare it to other tasks' general statements, you'll see that the general statement of this task is the simplest). graphical method is acceptable at SL and hence this IA is doable. but yes further proof can be done with topics taught only in HL, however not crucial. it can still be done through other ways. Reply Link to post Share on other sites More sharing options...
bomaha Posted November 8, 2011 Report Share Posted November 8, 2011 (edited) This is my teacher comments on this portfolio:It is so far beyond the SL syllabus that students will not be able to do much in the way of justification, formal or informal. For SL, this task should have stopped after the first page.I personally think it's still possible since it's just using calculator to count the sums and the general formula is very simple anyway (if you compare it to other tasks' general statements, you'll see that the general statement of this task is the simplest). graphical method is acceptable at SL and hence this IA is doable. but yes further proof can be done with topics taught only in HL, however not crucial. it can still be done through other ways.I know that this task is simple and finding the general statement is obvious (it's the simplest) once the data are put in tables and graphed. But my teacher meant that the any kind of proof, formal or informal is far beyond the SL syllabus. Edited November 8, 2011 by bomaha Reply Link to post Share on other sites More sharing options...
dessskris Posted November 9, 2011 Report Share Posted November 9, 2011 (edited) But my teacher meant that the any kind of proof, formal or informal is far beyond the SL syllabus.actually not really... SL students are kinda expected to be able to give informal proof, which is the validating the general statement part (which can be done in two ways: giving informal proof or considering further examples). I said "kinda" because it's not explicitly stated by them, but it's implied that they want it. proof:Criterion D : results5 The student gives a correct, informal justification of the general statement.(source: Maths SL Syllabus, 2008, page 47)perhaps by "justification" they didn't mean proof but I can see what they're hinting at. Edited November 9, 2011 by Desy Glau Reply Link to post Share on other sites More sharing options...
saleen Posted November 19, 2011 Report Share Posted November 19, 2011 What do they mean by a ''general statement''? anyone? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 19, 2011 Report Share Posted November 19, 2011 What do they mean by a ''general statement''? anyone?it's a formula, a general formula which works for all values of x and a and n Reply Link to post Share on other sites More sharing options...
bonvogue Posted November 26, 2011 Report Share Posted November 26, 2011 Hi everyone, I'm new here and this seems like a very helpful environment.I'd like to ask because I'm having a hard time trying to figure this out. I keep "hearing" that the general statement of the first page where x=1 and a=2 or x=1 and a=3 is a^x. I was wondering if someone could guide me as to how this is what they came up to. I don't want a full explanation, maybe just examples that would guide me to get this. Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 hi, yes we try to build a helpful environment here. come and ask when you have any question!hmmm, I'm afraid it would be difficult to explain unless you've done the paper. it's not that I don't want to help, but I think that you should do the task first. just do it. don't worry about getting the general statement, just start doing it first. you'll eventually see this pattern! then, if you just want to confirm again why this is so or something like that, you can go back here.gaining knowledge on your own feels so much better than just getting someone to share knowledge with you. Reply Link to post Share on other sites More sharing options...
bonvogue Posted November 26, 2011 Report Share Posted November 26, 2011 hi, yes we try to build a helpful environment here. come and ask when you have any question! hmmm, I'm afraid it would be difficult to explain unless you've done the paper. it's not that I don't want to help, but I think that you should do the task first. just do it. don't worry about getting the general statement, just start doing it first. you'll eventually see this pattern! then, if you just want to confirm again why this is so or something like that, you can go back here. gaining knowledge on your own feels so much better than just getting someone to share knowledge with you. Thank you I've already calculated what I need for the 3 parts on the first page (x=1 and a=2 & x=1 and a=3 & x=1) and graphed the relationships, I'm just confused as what I'm supposed to look at when you mention patterns. Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 don't all the graphs approach a certain value as n increases? Reply Link to post Share on other sites More sharing options...
bonvogue Posted November 26, 2011 Report Share Posted November 26, 2011 don't all the graphs approach a certain value as n increases?Yup they do, depending on what the value of a is it is close to is what n approaches to when x=1. It makes sense in the statement for example when a=2, it approaches 2, therefore I see the correlation as when you plug in the values for a and x into the general statement, it equals to the sum. I still don't understand what I'm looking for on these graphs to be honest, they all represent the same curve. Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 what a great explanation! you actually got it. the pattern is that the sum to infinity reaches a certain value, which I'm pretty sure you know. that's it. Reply Link to post Share on other sites More sharing options...
bonvogue Posted November 26, 2011 Report Share Posted November 26, 2011 (edited) what a great explanation! you actually got it. the pattern is that the sum to infinity reaches a certain value, which I'm pretty sure you know. that's it. LOL Desy are you saying I answered my own question? Haha thank you Edited November 26, 2011 by bonvogue Reply Link to post Share on other sites More sharing options...
eseb Posted November 29, 2011 Report Share Posted November 29, 2011 Uhh sorry I am not really helpful in here..instead I am confusing people! Sorry sorry! How do you find the equation mathematically? It says explain how you arrived at the equation mathematically.... Do it by algebra..? okay, after carefully reading many of these posts, i want to clarify. in total, there should only be ONE general statement? that would mean the sentence at the bottom (use your observations . . . find a general statement) goes along with the back of the page? As Summer Glau said, yeah one general statement Sorry I was confused because I think some people referred to S∞ on the first page as a general statement so I thought there were 2 general statements hahaha There is only one GS then, which is the one you just mentioned I am starting to get really confused here, when it says "use your observations from these investigations to find a general statement that represents that infinite sum of this general sequence" on the first page, that is where we state a^x? or do we just say that the value of a is equal to the asymptote of the graph? and if we have to state that a^x is the general statement for the first page, if you try finding the infinite sum for x=2 and a=2 the sum is 2 and according to the formula a^x it should equal 4. i am really confused please helppp!!! thanks in advance Reply Link to post Share on other sites More sharing options...
eseb Posted November 29, 2011 Report Share Posted November 29, 2011 Hey everyone, do this assignment on your own, this thread will just confuse you, it did not help me at all. Also you will get more out of it by doing it by yourself. Just go and do it by yourself and it will be much better. It will take less time to find out what to do on your own than looking through this thread, because it is just very confusing, no offence to the guys who tried to help.Also take a look at the Taylor Series for finding the equation a^x mathematicallydo that mean that the general statement a^x does not refer to the first page of the portfolio, because i cannot see how it is going to work. for the last bit "use your observations from these investigations to find a general statement that represents that infinite sum of this general sequence" we have to just state what we observe in words? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 29, 2011 Report Share Posted November 29, 2011 observe the pattern in the results, describe it in words. then, formulate a general statement. at this stage, x=1 so a^x=a, so at this stage you do not know yet that the formula is a^x. you only know that it's a. and then, you'll test for other values of x, and you find that hey it doesn't just approach a, it approaches a^2 when x=2, it approaches a^3 when x=3, etc. so then you conclude that it's a^x for x=2 and a=2, the sum is 2? you sure? maybe you made a calculation mistake? Reply Link to post Share on other sites More sharing options...
eseb Posted November 30, 2011 Report Share Posted November 30, 2011 observe the pattern in the results, describe it in words. then, formulate a general statement. at this stage, x=1 so a^x=a, so at this stage you do not know yet that the formula is a^x. you only know that it's a. and then, you'll test for other values of x, and you find that hey it doesn't just approach a, it approaches a^2 when x=2, it approaches a^3 when x=3, etc. so then you conclude that it's a^x for x=2 and a=2, the sum is 2? you sure? maybe you made a calculation mistake? oh ok thank you very much, so for the stage i am at i just have to right that S(inifinity)= a Reply Link to post Share on other sites More sharing options...
eseb Posted November 30, 2011 Report Share Posted November 30, 2011 observe the pattern in the results, describe it in words. then, formulate a general statement. at this stage, x=1 so a^x=a, so at this stage you do not know yet that the formula is a^x. you only know that it's a. and then, you'll test for other values of x, and you find that hey it doesn't just approach a, it approaches a^2 when x=2, it approaches a^3 when x=3, etc. so then you conclude that it's a^x for x=2 and a=2, the sum is 2? you sure? maybe you made a calculation mistake? oh ok thank you very much, so for the stage i am at i just have to right that S(inifinity)= a i also want to ask you, for the second part, it says that we have to graph between T9(2,x) and x what does that mean i plot what against what? i plot the value of Sn for different values of x? so i find T9(2,2) and the S(infinity) of this is one point? thank you very much! Reply Link to post Share on other sites More sharing options...
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