Razzker Posted September 10, 2011 Report Share Posted September 10, 2011 (edited) Sorry for asking so many questions. I have found that the general statement is ax, but I don't see any limitations to this general statement. Any help? Hints maybe?Also, I know that the Taylor expansion works for this paper, but I cannot explain how I know this. I don't think the teacher will believe me if I just say that I found the equation on MS Word and that it matches. Haha. Edited September 10, 2011 by Razzker Reply Link to post Share on other sites More sharing options...
dessskris Posted September 10, 2011 Report Share Posted September 10, 2011 (edited) it's okay, it's not very many I've got A LOT more questions than that. a few more won't hurt. the limitation, what if a and x becomes zero? what if they become negative? what if they become fractions? what if they become surds? etc... stuff like that. lol, I don't know... I mean, I was also only told by someone a long long time ago. maybe say that you are reminded of this formula... and if your teacher asks, just say you found it from the internet when researching on this task. I think someone said it's in their textbook or something like that. can you try looking it up in your book? maybe you can find it there EDIT: it's in the HL syllabus! just say some HL student told you about it or something? Edited September 10, 2011 by Desy Glau 1 Reply Link to post Share on other sites More sharing options...
Razzker Posted September 10, 2011 Report Share Posted September 10, 2011 Let's just say I researched online. Hehe ...Anyway, I'm almost done with the portfolio. Thank you so much for your help. I finally found a way to explain how I got the general statement and all I need to do now is to complete the document with headers and footers, a cover page and other fancy stuff. Reply Link to post Share on other sites More sharing options...
Priyanka Posted September 15, 2011 Report Share Posted September 15, 2011 you can also program your calculator and you can explain it in the IA and all you have to do is plug in the X and A values instead of it being too tedious Reply Link to post Share on other sites More sharing options...
Moe1943 Posted September 16, 2011 Report Share Posted September 16, 2011 could anyone please send me, the image with the guide!! please i really need it! Reply Link to post Share on other sites More sharing options...
dessskris Posted September 17, 2011 Report Share Posted September 17, 2011 could anyone please send me, the image with the guide!! please i really need it! what image and what guide? you mean the question paper? Reply Link to post Share on other sites More sharing options...
hugo262 Posted September 17, 2011 Report Share Posted September 17, 2011 (edited) Hey so I was wondering what the implications are for the series if a is negative, or even an imaginary number, a square root of a negative number. Does anyone have any ideas on these as excel just came up with errors for ives and imaginery values of a? Edited September 17, 2011 by hugo262 Reply Link to post Share on other sites More sharing options...
dessskris Posted September 18, 2011 Report Share Posted September 18, 2011 it means a cannot be imaginary or negative, it's your limitation Reply Link to post Share on other sites More sharing options...
laneey Posted September 21, 2011 Report Share Posted September 21, 2011 (edited) for the first section where x=1, the general statement is that n=sn where n is the limit for sn. however on the second part of it when you change the x value, the general statement is a^x i found at first that my statement was ax but double and triple check your equation (i used excel) because if you don't write it right then this is the pattern you'll get!! hope this saves time as it wasted a lot of mine!!! Good luck IBlets Edited September 21, 2011 by laneey Reply Link to post Share on other sites More sharing options...
Jerald Posted September 26, 2011 Report Share Posted September 26, 2011 Can anyone teach me how to plot the relationship between Sn and n? How do you plot something if you don't know its function and only the points? Reply Link to post Share on other sites More sharing options...
dessskris Posted September 27, 2011 Report Share Posted September 27, 2011 use your GDC. if you have TI, start a new spreadsheet page, tabulate the n and Sn, and then start a new statistics page, input the variables and choose which regression type you'd like to find.otherwise you can just plot it in excel and generate the trendline like in a science IA. 1 Reply Link to post Share on other sites More sharing options...
Jerald Posted September 27, 2011 Report Share Posted September 27, 2011 Okay, thanks! I ended up using Geogebra to graph because I already did my calculations on the GDC and maunally copied to Word in MathType, so I didn't want to retype everything in Excel. I'm at the last part of the portfolio now; does anyone mind explaining the difference between the validity and scope/limitations of the general statement? Are they both just values of a and x that would result in the statement being false? IF so should I group them into one category? Also, is continue with this analysis to find the gernal statement... the same thing as explain how you arrived at the general statement? IB.. so many command terms and questions.. Reply Link to post Share on other sites More sharing options...
dessskris Posted September 27, 2011 Report Share Posted September 27, 2011 oh you can do it in Ms.Word too. can't believe you didn't know that! use the chart feature thing. but oh well. validity: they're asking for some kind of 'informal' proof. if you could give a formal, mathematical prove (which is not expected at SL level, only at HL) that would be super awesome. otherwise you could try for some other values of a and x, investigate and check with your general statement. scope/limitations: what can a and x be? can they be zero? can they be negative? can they be decimals? can they be pi or e? etc... and is there any other limitation? well you'll have to figure that out. yes this part is asking for values of a and x where the general statement will be false. no don't group them into one category. and sorry i don't quite understand your last question? when they ask you to explain how you arrived at the general statement, well they wonder how you got the formula I personally think this could be explained when you are about to generate the general statement, but that's just me. ask your teacher for some certainty. Reply Link to post Share on other sites More sharing options...
Jerald Posted September 27, 2011 Report Share Posted September 27, 2011 Oh.. a bit too late for that now Thanks for your help! The questions just sound really similar.. Reply Link to post Share on other sites More sharing options...
nobrega Posted October 7, 2011 Report Share Posted October 7, 2011 Hey guys, i just got my internal assessment today.I really did not understand anything that the assignment says. However after reading this post I have noticed that there are some ideas of the general statement being a^x or ax What is this whole idea behind Taylor's Expansion, i looked it up online and it seems to be the answer to the whole calculations to ultimately find the general statement.Is there anyone out there that could help me and give me a direction that I could followthank you soo much. Reply Link to post Share on other sites More sharing options...
testthek1 Posted October 8, 2011 Report Share Posted October 8, 2011 I'm actually retarded so I don't even know how to do the first question, where it says Calculate the sum Sn of the fist n terms of the above sequence. What am I supposed to do? I punched in the numbers on my graphing calculator but nothing really stood out... Reply Link to post Share on other sites More sharing options...
dessskris Posted October 9, 2011 Report Share Posted October 9, 2011 to both of you, and all the other people who need help, the outline for this IA can be found here: Taylor expansion can be used to prove or validate the general statement. if you still don't get the answer to your question from the very detailed outline, ask again. but please quote me so I get a notification so I can reply to you as soon as I check this website. Reply Link to post Share on other sites More sharing options...
dessskris Posted October 12, 2011 Report Share Posted October 12, 2011 Hey so I am at the part where you have to calculate the sum of the first ten terms when x=1 and a is not defined. How can I add the different values to a sum if T1= (ln a)/1! and T2= (ln a)/2! and so forth? lol you're so cute! you should set the values of a by yourself, I suggest trying for at least 3-5 different values of a. then you should see a pattern and generalise for any value of a Reply Link to post Share on other sites More sharing options...
CamilleRodriguez Posted October 15, 2011 Report Share Posted October 15, 2011 someone pleeeeeaaase help me i dont get it... what do i have to do? Reply Link to post Share on other sites More sharing options...
Emmi Posted October 15, 2011 Report Share Posted October 15, 2011 This thread should be very helpful. You can read through what others have posted and if you don't see what you are looking for you can post there and someone will try to help you. I didn't have this portfolio for my IA, but good luck! Reply Link to post Share on other sites More sharing options...
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