SharkSpider Posted November 18, 2008 Report Share Posted November 18, 2008 To prove the conjecture in three, simply employ the quadratic formula, by setting all of your terms to variables, IE, ax^2 + bx + c. 1 Reply Link to post Share on other sites More sharing options...
shining.clover Posted November 18, 2008 Report Share Posted November 18, 2008 Hey!Im doing that too.1-4 was easy. but im stuck in 5-6...but i probably gonna figure out tomorrow i need help if i dont figure it out!!Hey!Im doing that too.1-4 was easy. but im stuck in 5-6...but i probably gonna figure out tomorrow i need help if i dont figure it out!! Reply Link to post Share on other sites More sharing options...
DJVM Posted November 19, 2008 Report Share Posted November 19, 2008 Eh. How do you even prove the conjecture in #3?Me so confused.In q.3 u need to take values of a<0 ye.so u basically do tht take -2 , -3 , -5/6 take lik 3-4 different a values change b n c to ensure ur prabola intersects both lines. Derive a conjecture using these examples ull get sumin lik D=1/|a| ..now to PROVE your conjecture all u have to do is graph it. Graph D=1/|a| in the form of y=1/|x|.. u get a hyperbola. find the H.A. of the hyperbola which wil be x=0 which is the limitation to your conjecture..thats it !! u do the same in q.2 graph ur conjecture y=1/a n show limitations. Reply Link to post Share on other sites More sharing options...
DJVM Posted November 19, 2008 Report Share Posted November 19, 2008 Hey!Im doing that too.1-4 was easy. but im stuck in 5-6...but i probably gonna figure out tomorrow i need help if i dont figure it out!!Hey!Im doing that too.1-4 was easy. but im stuck in 5-6...but i probably gonna figure out tomorrow i need help if i dont figure it out!!k so uve done q.4 right..need a lil help there im stuck !! n i gotta hand in my portfolio tomoro ..wat is the conjecture u get in q.4 ..do u only take lines cutting the origin or even lines which intersect at points other than 0,0 ?? im so fukin confused !!! y do i always leave **** for the last minute !! some help please im dun with 1-3 !! n im soo not looking forward to 5-6 all the posts ask for help with them !!! Reply Link to post Share on other sites More sharing options...
theblackraven Posted November 20, 2008 Report Share Posted November 20, 2008 k so uve done q.4 right..need a lil help there im stuck !! n i gotta hand in my portfolio tomoro ..wat is the conjecture u get in q.4 ..do u only take lines cutting the origin or even lines which intersect at points other than 0,0 ?? im so fukin confused !!! y do i always leave **** for the last minute !! some help please im dun with 1-3 !! n im soo not looking forward to 5-6 all the posts ask for help with them !!!#4 was hard. I actually sort of skipped it. #5 is easy! Just label the points the same as in #1 and #2 (you'll have two extra points, duh) and apply an equation for D. Its an interesting answer. You dont have to prove it, so I guess it's okie to leave the conjecture a bit vague. And not shure about #6. Not been much help, sorry. Reply Link to post Share on other sites More sharing options...
CellarDoor Posted November 21, 2008 Report Share Posted November 21, 2008 Guys,This is the easiest Type 1 portfolio there is this year. It is not as complicated as it seems.All you have to do is play around with the numbers you have, try to relate to other things you know about quadratics... and if you get something that is not true to your conjecture (such as D=0), then it probably is not right. You have to gid deeper into the problem, live it, or else, Maths HL may not be for you. Reply Link to post Share on other sites More sharing options...
michaellwh Posted November 23, 2008 Report Share Posted November 23, 2008 I have finish this ia already. to give you guys some hintfor part five, the conjecture would be SL = x2 ‐x1‐ S1 = x4 –x3‐ SR = x6 –x5D = | SL ‐ S1 ‐ SR |=0for part 6 use sum of root to prove your conjecture, if you have any? pm mehopes that helpsthanks Reply Link to post Share on other sites More sharing options...
speedo Posted November 24, 2008 Report Share Posted November 24, 2008 hello, Can someone help me with the introduction of the investigation. What do we have to say in the intro? How much do we have to write for it?PM would be great.thank you :innocent: Reply Link to post Share on other sites More sharing options...
posse02 Posted November 26, 2008 Report Share Posted November 26, 2008 (edited) The introductions does not need to be that long,just give a general idea of the investigation and some background. (That's what I did, wasn't longer than a page)My teacher gave us a few samples and their intros where not long at all, and still got 19-20/20Finished the investigation and handed it in last week, thanks for all the help! Edited November 26, 2008 by posse02 Reply Link to post Share on other sites More sharing options...
Sanchez Posted November 28, 2008 Report Share Posted November 28, 2008 can anyone semd me please the answer for q2? Reply Link to post Share on other sites More sharing options...
Sanchez Posted November 28, 2008 Report Share Posted November 28, 2008 how do you do q5 and q6?please help me Reply Link to post Share on other sites More sharing options...
Sanchez Posted November 29, 2008 Report Share Posted November 29, 2008 how do you get D for q5? Reply Link to post Share on other sites More sharing options...
speedo Posted November 29, 2008 Report Share Posted November 29, 2008 how do you get D for q5?What is question 5? Reply Link to post Share on other sites More sharing options...
eguy4 Posted December 2, 2008 Report Share Posted December 2, 2008 one hint for all who are stuck on 5 and 6.look at vietta's formulaafter seeing this, ud better get it. if u dont, god help u cause ur gonna need a mircle 1 Reply Link to post Share on other sites More sharing options...
FlyByNight Posted December 2, 2008 Report Share Posted December 2, 2008 Hey guys,So I've been working on this for a really long time, but I have not really gotten anywhere. I have completed for the most part, questions 1 - 4. I am wondering about two things. First some have said to use the quadratic equation for the proof of my conjecture. I don't really understand how I am supposed to do this. I mean, I know how to use the quadratic formula, but I don't know how it applies here. Second, I am struggling on questions 5 and 6. People are saying to use Vietta's theorem, but until today, I hadn't even heard of it. I have looked it over, and I think that I can use it, but I have no idea how to use it. I would appreciate any help I can get, because frankly, I am over my head on the last two.Thanks,Peter Reply Link to post Share on other sites More sharing options...
kyska Posted December 6, 2008 Report Share Posted December 6, 2008 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 Reply Link to post Share on other sites More sharing options...
Venom Posted December 7, 2008 Report Share Posted December 7, 2008 Hey guys, I just got assigned the same damn Investigation...I'm looking for help of all sizes, but in particular, Question 5. (Any by default, 6)Basically, I've proven and written up the proofs for everything, and I do mean everything up until question 4.And thats when I burn out. So, I've been searching forums, and plugging into google, and here's literally all I've found.My conjecture for number 4 is accurate:D=|m2-m1|/|a|Now...how to apply that to cubic?I've never heard of Vieta's Theorum, but as far as I can tell from my reading of it, it is designed to evaluate the roots of a polynomial in relation to its parts.This is all well and good, but how the heck does that affect our conjecture? I thought maybe substituting some value for a, i.e. D=|m2-m1|/|-b/(x2-x1)|But isn't that just restating the obvious? I don't see how that is supposed to help the other values or even make D=0.Far as I can tell, D could only = 0 if m2-m1 is 0, right? Anything else is invalid.Thus, I plead for someone to either PM or post the solution, to at least number 5. If it emplyos Viettas theorum, so be it.I've seen:D=|Sm-Sl-Sr|=0, which is fine, but doesn't follow the proof (shouldn't it be lowest - highest x values? i.e (|Sr - Sl - Sm)?)D=|Dr-Dl| where Dr or Dl is some semblence of the two..._____________________________________________-In short, I think I'm in over my head. If anyone has even a pretense of a solution for 5, I'd be glad, even if I get nothing for 6.Hell, if someone could explain how Vieta, or rather, Viete's formula factors into the whole damn thing, I'd be satisfied.I feel so damn close to. Please? 1 Reply Link to post Share on other sites More sharing options...
SharkSpider Posted December 7, 2008 Report Share Posted December 7, 2008 You need to take a look at what is true, and then work on proving it. That means graphing cubics, taking roots, intersecting it with lines, and then coming to conclusions. It takes time and effort, and you need to think about it.The biggest hint you can get is to intersect the lines in equation format, ie. x = P(x), then 0 = P(x)+x, and then use that with vieta's formula to come up with the sum of the x values of the intersections. I discovered a few really interesting things myself, namely that in part 6 you can intersect two parabolas with a quartic and get similar results to when you intersect two lines with a cubic. Reply Link to post Share on other sites More sharing options...
kman Posted December 7, 2008 Report Share Posted December 7, 2008 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.mgala, do you study at stfx by any chance? Reply Link to post Share on other sites More sharing options...
Venom Posted December 8, 2008 Report Share Posted December 8, 2008 You need to take a look at what is true, and then work on proving it. That means graphing cubics, taking roots, intersecting it with lines, and then coming to conclusions. It takes time and effort, and you need to think about it.The biggest hint you can get is to intersect the lines in equation format, ie. x = P(x), then 0 = P(x)+x, and then use that with vieta's formula to come up with the sum of the x values of the intersections. I discovered a few really interesting things myself, namely that in part 6 you can intersect two parabolas with a quartic and get similar results to when you intersect two lines with a cubic.Alright, I guess I'll just keep graphing and hope I hit something...even though we have never done Vieta's formula in class...BTW, is the final conjecture completely different from what we had earlier? i.e, nothing to do with slopes and the a value then?Ah well, lemme see if there is a pattern in there...though I don't know how to interpret it...Thanks. Reply Link to post Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.