zaid93 Posted May 16, 2009 Report Share Posted May 16, 2009 (edited) i finished questions 1 and 2 ...they didnt take me much time..but what are you supposed to do in question 3? Edited May 18, 2009 by Mahuta Please do not use text speak in the forum, thanks- Maha :) Reply Link to post Share on other sites More sharing options...
samdefa Posted May 17, 2009 Report Share Posted May 17, 2009 I am s-t-ruggling for the proofs in questions 3 and 4 any help? Reply Link to post Share on other sites More sharing options...
CocoPop Posted May 19, 2009 Report Share Posted May 19, 2009 I am s-t-ruggling for the proofs in questions 3 and 4 any help?Think about how you would algebraically go about finding the intersections of two functions.For example if you have the functions f(x)=x^2 and g(x)=x, how would you find their intersections without a calculator? It's really simple, and you need to use a method that you will have learned long ago. You're dealing with quadratics, so there's quite a simple way of solving for x. Also, your proof has to work for quadratics in any form, so each term could have any coefficient.I hope that helps. Reply Link to post Share on other sites More sharing options...
CocoPop Posted May 19, 2009 Report Share Posted May 19, 2009 (edited) Hi, sorry for the double post, but I have a question myself. I was able to deduce a general formula for polynomials of any degree intersecting with a polynomial of any degree. In other words, all polynomials could be of different orders. Is this swaying a bit too far off the topic of the investigation or is it worth including?I would really appreciate a response as soon as possible as I have to hand this in tomorrow and won't be able to speak to my teacher until then. Edited May 19, 2009 by CocoPop Reply Link to post Share on other sites More sharing options...
suisue Posted June 19, 2009 Report Share Posted June 19, 2009 Guys, I am on question 3 where I have to prove it. I have used the sum and product of root thing and I have managed to calculate from this the conjecture that I deduce from the pattern. Is this enough as a proof or do I have to do some testing? I hope you guys who have done it get what I mean. Reply Link to post Share on other sites More sharing options...
Guest gankeel Posted June 20, 2009 Report Share Posted June 20, 2009 Do you guys know what the hidden aim and the aim of the investigation is? I need to write it into my intro? Reply Link to post Share on other sites More sharing options...
rrswong Posted July 7, 2009 Report Share Posted July 7, 2009 There's a hidden aim? I didn't know that.. I did this investigation, and I didn't have an introduction of any kind, and I got 19/20.. marked down in criterion C. Suisue, you can do it as a proof or from graphing it, it doesn't matter. Reply Link to post Share on other sites More sharing options...
aya91 Posted November 11, 2009 Report Share Posted November 11, 2009 Ok so I am currently in the midst of part 4... and this is due tomorrow. What happens if you hand it in sort of... half done? do you still get some points, or do you fail math altogether? Reply Link to post Share on other sites More sharing options...
SharkSpider Posted November 13, 2009 Report Share Posted November 13, 2009 aya91: Stay up till 6 AM if you have to, but get as many of the questions answered as you possibly can. I don't need to mention that these things need time and have to be started early, but the more the better. Generally, going up to question 4 will get around 8 to 9 points, if I remember correctly, but that was loosely based off what my teacher said. That's also not bad, considering people who do the whole thing end up with 8 or 9, rather often.Hmm.. whats the average length of a type 1 IA? Mine in total turned out to be ~24 pages but with spacing for graphs, etc. but I covered all points and tried not to be repetitive. so I don't know about that..I got a 20 with mine, and it was 3 and a half pages, total. In addition to that, I can quote my math teacher saying that anyone who went over 5 pages on this particular assignment missed the boat at question three, but elaborating would make it too easy to find out why. The main "reason" is that the 24-page people have that much because they write and write and do example after example to justify their claim, when the proof is three or four lines long. My question 5 looked like one example, that I did in maple so I just wrote the answer, then I wrote a conjecture and a 4 line proof, then did the same for question 6. Those two, combined, were half a page, simply because IB doesn't ask for examples or tests for the last two questions.Anyways, some questions to ask yourself: What are you really doing to these polynomials? What is a polynomial? What characteristics does a polynomial have?As a final note, if you use the quadratic formula in any part of your proofs, you're on the wrong track, the proof can be made about 1/5 as long as yours will be. 1 Reply Link to post Share on other sites More sharing options...
ocfx Posted December 11, 2009 Report Share Posted December 11, 2009 Hi,Okay I'm doing this same investigation now its do next Friday so I still have time. I have not got to 5. or 6. yet, but in terms of 3. and 4. how do I rule out the lines that will not intersect the parabola at least twice. That is, I have a sound conjecture, but I don't know how to limit it to only the lines that will allow for D. On the side of proving my conjecture should I try to use the general form of the parabola and the gradient for the linear lines or do something else?Any help will be appreciated =D Reply Link to post Share on other sites More sharing options...
ConfusedMuch Posted December 14, 2009 Report Share Posted December 14, 2009 Hello, so i'm still on part two, trying to prove what i think could be a conjecture by putting up examples. I'm starting to wonder if there isn't a way to speed that up and was wondering if anyone has any tips maybe, that would be appreciated, this investigation is so confusing to me. Reply Link to post Share on other sites More sharing options...
HansTheParabolaMan Posted January 30, 2010 Report Share Posted January 30, 2010 What background knowledge should one have to tackle this problem? Which IB math chapters? I take it one needs Mathematical Induction for writing the proof, but what else? Integration (Areas and Other Applications)?What's D lol? A derivative of something or what? Reply Link to post Share on other sites More sharing options...
Worked Posted March 7, 2010 Report Share Posted March 7, 2010 okay i've got #1 and #2 and that's all i have. I need help Reply Link to post Share on other sites More sharing options...
adityakumar Posted March 7, 2010 Report Share Posted March 7, 2010 Hello, so i'm still on part two, trying to prove what i think could be a conjecture by putting up examples. I'm starting to wonder if there isn't a way to speed that up and was wondering if anyone has any tips maybe, that would be appreciated, this investigation is so confusing to me.What you want to do is go after it algebraically - That's how I got it. Reply Link to post Share on other sites More sharing options...
chanweian Posted July 20, 2010 Report Share Posted July 20, 2010 so for question 3, what do i make the quadratic equation equal to?because doesnt the equation give you the x-intercepts, but we are looking for the intercepts with y=x and y=2x? Reply Link to post Share on other sites More sharing options...
smartypants093 Posted December 6, 2010 Report Share Posted December 6, 2010 Can anyone help me with the parabola investigation? I am stuck in number 5 and 6. Thanks!Sl=x1-x2Sr=x3-x4D= abs( Sl-Sr)5.Determine whether a similar conjecture can be made for cubic polynomials6. Consider whether the conjecture might be modified to include higher order polynomials.How would you find D for the cubic regression? Since you would have 6 intersections instead of only 4? Is it:Sl=x3-x2-x1Sr=x6-x5-x4D=abs(Sl-Sr)????I got a 20 with mine, and it was 3 and a half pages, total. In addition to that, I can quote my math teacher saying that anyone who went over 5 pages on this particular assignment missed the boat at question three, but elaborating would make it too easy to find out why. The main "reason" is that the 24-page people have that much because they write and write and do example after example to justify their claim, when the proof is three or four lines long. My question 5 looked like one example, that I did in maple so I just wrote the answer, then I wrote a conjecture and a 4 line proof, then did the same for question 6. Those two, combined, were half a page, simply because IB doesn't ask for examples or tests for the last two questions.Anyways, some questions to ask yourself: What are you really doing to these polynomials? What is a polynomial? What characteristics does a polynomial have?As a final note, if you use the quadratic formula in any part of your proofs, you're on the wrong track, the proof can be made about 1/5 as long as yours will be.Hi sharkspider,So I have no idea how to go about writing a formal proof. What math theorems need to be incorporated into it? Reply Link to post Share on other sites More sharing options...
timtamboy63 Posted February 13, 2011 Report Share Posted February 13, 2011 Hey guys. Just wondering if anyone thats done this would be willing to show me what they've done? Basically, my teacher gave it to us as a practice, due tomorrow. I forgot about it, and haven't started yet Help please Reply Link to post Share on other sites More sharing options...
heyit'salison Posted March 29, 2011 Report Share Posted March 29, 2011 Hey, I am doing this portfolio as well. 1-4 are very eqasy, if any1 have questions PM. I'm stuck at 5 as many of you:( I do not get D = O. I'm taking always exact values, maybe that's a problem, but when I'm rounding the answer it still does not get exact zero Ohmykebab. I have no idea how to do the entire investigation! My teacher just gave it to me, and worst is i'm the only student in the whole school doing math HL, so i can't ask anyone for helpPlease help meeee, ANYONE! I've done question 1, but idk what values to use for q2 and q3 etc.. Reply Link to post Share on other sites More sharing options...
adityakumar Posted March 29, 2011 Report Share Posted March 29, 2011 Hey, I am doing this portfolio as well. 1-4 are very eqasy, if any1 have questions PM. I'm stuck at 5 as many of you:( I do not get D = O. I'm taking always exact values, maybe that's a problem, but when I'm rounding the answer it still does not get exact zero Ohmykebab. I have no idea how to do the entire investigation! My teacher just gave it to me, and worst is i'm the only student in the whole school doing math HL, so i can't ask anyone for helpPlease help meeee, ANYONE! I've done question 1, but idk what values to use for q2 and q3 etc..questions 2 and 3 are mostly just algebraic ways of finding general rules instead of specific examples. Reply Link to post Share on other sites More sharing options...
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