etc Posted November 11, 2010 Report Share Posted November 11, 2010 isnt the recursive rule R(n)=R(n-1)+n where R(n) is the number of pices after n cuts?I have no idea if this is supposed to be the conjecture and I certainly dont know how to prove it Reply Link to post Share on other sites More sharing options...
ibes Posted November 30, 2010 Report Share Posted November 30, 2010 isnt the recursive rule R(n)=R(n-1)+n where R(n) is the number of pices after n cuts?I have no idea if this is supposed to be the conjecture and I certainly dont know how to prove itdoes mathamatical induction work? i have the same portfolio due tomorrow morning and would really like to have some kind of help on this. I'm currently stuck on the 3-D cube. Im trying to use archimedes geo to make the cube. anyone done with the portfolio and wish to help? Reply Link to post Share on other sites More sharing options...
Access Denied Posted December 2, 2010 Report Share Posted December 2, 2010 I find it funny how people call it the easy route really it's just like someone taking sl English , it depends on what you are good at, don't make things harder for yourself unless your trying to be a doctor or something Reply Link to post Share on other sites More sharing options...
kiwi.at.heart Posted December 2, 2010 Report Share Posted December 2, 2010 At my school, its baiscally recommended if you dont need Maths SL and you dont really enjoy maths that you should do studies. Also, in studies, if you put in the effort, I is quite possible to get a good mark. I had a friend who was struggling in SL and was getting a 3. She moved to studies and not is getting a 6, which would look a lot better in the end. Reply Link to post Share on other sites More sharing options...
Maddyy Posted December 2, 2010 Report Share Posted December 2, 2010 (edited) We figured out a pattern for the third one, but I really don't understand it and I still need to type up my IA...Excel helps a lot, if you know how to use it, especially for finding a recursive rule. Also, its a use of technology if you don't want to use the 3D software. (No one in my class has even found any that works, except for a girl whose dad has it on his computer cos he works at Boeing...) Edited December 2, 2010 by Maddyy Reply Link to post Share on other sites More sharing options...
De Code Master Posted December 3, 2010 Report Share Posted December 3, 2010 I'm doing independent study math HL (the rest of the class chickened out... ) and I've gotten answers up to the third dimension, but I don't know if the deduction and recursive sequence are correct. Are we supposed to include our formula R=X+S in our formula for P=Y+X+S? Is it the same x? I still can't find a pattern for all of the different formulae.etc and ibes, I got that recursive rule and proved it through the k+1 induction type. Forget what it's called, but it works out nicely. On the other hand, here is a dutch applet called Doorzien that allows 3d modelling of a cube cut by planes. You can make the cube clear on the right hand side, and using the little plus arrow plane allows the planes to be solid. Clicking the separate button and then clicking on a line allows separation of the cube along this plane. It's really useful for counting, and it's how I got the solutions for the 3d part. (sorry about the vague directions; I don't speak Dutch, only a bit of german! A lot of the stuff I did was just experimentation.)http://www.fi.uu.nl/toepassingen/00349/leerling.htmlGood luck! Reply Link to post Share on other sites More sharing options...
seigakufuji Posted December 6, 2010 Report Share Posted December 6, 2010 So I am working on this portfolio too and I am stuck on the technology part. What are we supposed to use for technology? a software or something?? Some help will be really appreciated!! Reply Link to post Share on other sites More sharing options...
chrypton Posted December 6, 2010 Report Share Posted December 6, 2010 So I am working on this portfolio too and I am stuck on the technology part. What are we supposed to use for technology? a software or something?? Some help will be really appreciated!! Yes, you are suppose to use a computer or a calculator that ""significantly enhances" your portfolio. This could be anything from using Excel to compute faster, or using a graph program to visually present your results. Reply Link to post Share on other sites More sharing options...
Julie Posted December 7, 2010 Report Share Posted December 7, 2010 I dread the thought of talking Math HL next yearWhy do you have to take Math HL next year?! I don't get it..Are you currently finding SL hard?I'm in 11th grade taking Math SL right now, and i'm good at it. next year is HL and i have heard that it drives people towards suicide (jk There's something wrong here... you either take SL for two years or HL for two years. It's not like two one year courses... there are three categories (basically):- Math HL- Math Sl- Math StudiesAnd you take any of these for two years, normally.idk but at my school you take sl in 11th grade and then hl in 12th gradeyou have an option to go down to studies if you don't want to take hl in 12th grade (senior year)That makes no sense, you should be allowed to be in any of them if your school offers them all. Maybe you should talk to your IB Coordinator about it. She/He might have some information you don't know about. If yo uare in HL now and are doing ok, but would like an easier course, switch to SL, not Math studies. Math studies would be a breeze for you. And also, if your university asks for SL you definitely need to take it. Reply Link to post Share on other sites More sharing options...
Jessamine Posted December 8, 2010 Report Share Posted December 8, 2010 Can someone help me with the 4D part? I need to hand this in tomorrow, which basically 6 hours from now! TT^TT Reply Link to post Share on other sites More sharing options...
Guest JimmyK Posted January 8, 2011 Report Share Posted January 8, 2011 I'm doing that as well.. And I'm stuck on n=6! :/you don't have to do n = 6 ? the task says investigate maximum number of parts for n = 1,2,3,4 and 5but usually you have to investigate more than what is asked... Reply Link to post Share on other sites More sharing options...
dessskris Posted January 8, 2011 Report Share Posted January 8, 2011 I'm doing that as well.. And I'm stuck on n=6! :/you don't have to do n = 6 ? the task says investigate maximum number of parts for n = 1,2,3,4 and 5but usually you have to investigate more than what is asked...But not in that sense. If they specificly ask for n=1,2,3,4 and 5 then you won't need to find it when n=6. I don't have access to the portfolio question currently (my PDF reader is broken) so I can't make a guess where you can investigate more than what is asked. Will get back to you tomorrow.EDIT: since they ask you the relationship between the max number of parts and the number of cuts in 1D, 2D, 3D and 4D objects, if you want to go extra mile you need to find the general relationship in nD object Reply Link to post Share on other sites More sharing options...
Sever Seifer Posted January 21, 2011 Report Share Posted January 21, 2011 hellooo im new here. but im taking IB and also HL Math. i am also currently doing 'How many pieces'ive just done 3D last night. but i cant figure out about the 4D, can anyone tell me?and to prove your conjecture, we prove the recursive formula or the original formula? if recursive, how? because recursive formula is with Tn. and im stuck with it. im looking for a solution. thx Reply Link to post Share on other sites More sharing options...
Guest JimmyK Posted January 23, 2011 Report Share Posted January 23, 2011 hellooo im new here. but im taking IB and also HL Math. i am also currently doing 'How many pieces'ive just done 3D last night. but i cant figure out about the 4D, can anyone tell me?and to prove your conjecture, we prove the recursive formula or the original formula? if recursive, how? because recursive formula is with Tn. and im stuck with it. im looking for a solution. thxIf you tabulate the results that you got for 1D, 2D and 3D, you'll notice a trend though you'll have to use something that is called "Method of Finite Differentiation". Then, you'll be able to have extrapolated values for 4D, 5D, 6D and n-D, easy as that ;D. After that, you can get a conjecture out of the data as you did for the other dimensions ^^. However, that's just extrapolating... Reply Link to post Share on other sites More sharing options...
Sever Seifer Posted January 25, 2011 Report Share Posted January 25, 2011 (edited) hellooo im new here. but im taking IB and also HL Math. i am also currently doing 'How many pieces'ive just done 3D last night. but i cant figure out about the 4D, can anyone tell me?and to prove your conjecture, we prove the recursive formula or the original formula? if recursive, how? because recursive formula is with Tn. and im stuck with it. im looking for a solution. thxIf you tabulate the results that you got for 1D, 2D and 3D, you'll notice a trend though you'll have to use something that is called "Method of Finite Differentiation". Then, you'll be able to have extrapolated values for 4D, 5D, 6D and n-D, easy as that ;D. After that, you can get a conjecture out of the data as you did for the other dimensions ^^. However, that's just extrapolating...Thanks for that but ive never been taught about that but i solved already solved it though, just that i dont know what spreadsheet to use for the 4d. Edited January 25, 2011 by Mahuta ♥ No text speak please. :) Reply Link to post Share on other sites More sharing options...
Guest JimmyK Posted January 26, 2011 Report Share Posted January 26, 2011 hellooo im new here. but im taking IB and also HL Math. i am also currently doing 'How many pieces'ive just done 3D last night. but i cant figure out about the 4D, can anyone tell me?and to prove your conjecture, we prove the recursive formula or the original formula? if recursive, how? because recursive formula is with Tn. and im stuck with it. im looking for a solution. thxIf you tabulate the results that you got for 1D, 2D and 3D, you'll notice a trend though you'll have to use something that is called "Method of Finite Differentiation". Then, you'll be able to have extrapolated values for 4D, 5D, 6D and n-D, easy as that ;D. After that, you can get a conjecture out of the data as you did for the other dimensions ^^. However, that's just extrapolating...Thanks for that but ive never been taught about that but i solved already solved it though, just that i dont know what spreadsheet to use for the 4d.Yeah well, that's the part where you have to do the resarch and investigation you can simply use excel...it works perfectly for this. Just a question, what rule did you get to? And if you did, how did you prove it?? Reply Link to post Share on other sites More sharing options...
exigen Posted February 4, 2011 Report Share Posted February 4, 2011 I've currently finished this portfolio but its 10 pages long...I think its too short, how about yours? Reply Link to post Share on other sites More sharing options...
yashdjoshi Posted February 4, 2011 Report Share Posted February 4, 2011 (edited) n= 1 is 2 piecesn=2 is 4 piecesn=3 is 8 piecesn=4 is 15 piecesn=5 is 26 piecesbasically for n= x the number of pieces are n=n(x-1) + the number of pieces for 2dimension for x-1 cuts.so for example n= 6 will be 26 + n( 2 dimension for 5 cuts) = 26 + 16 = 32 Edited February 4, 2011 by yashdjoshi Reply Link to post Share on other sites More sharing options...
Guest JimmyK Posted February 4, 2011 Report Share Posted February 4, 2011 I've currently finished this portfolio but its 10 pages long...I think its too short, how about yours?Yeah, I'd say it's too short...I've got 7 pages from just sketching the answers lol I guess you must need to develop more the concepts and the explanations...n= 1 is 2 piecesn=2 is 4 piecesn=3 is 8 piecesn=4 is 15 piecesn=5 is 26 piecesbasically for n= x the number of pieces are n=n(x-1) + the number of pieces for 2dimension for x-1 cuts.so for example n= 6 will be 26 + n( 2 dimension for 5 cuts) = 26 + 16 = 32That's basically the Method of Finite Differentiation... Reply Link to post Share on other sites More sharing options...
yashdjoshi Posted February 5, 2011 Report Share Posted February 5, 2011 isnt the recursive rule R(n)=R(n-1)+n where R(n) is the number of pices after n cuts?I have no idea if this is supposed to be the conjecture and I certainly dont know how to prove itThe recursive is right and one can prove the conjecture by mathematical Induction. Reply Link to post Share on other sites More sharing options...
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