IA Type II -- Gold Medal Heights

[IBaGurl1994]

how so? matrices in what way? i only learned so much with matrices that relating what i know right now doesnt help me in this problem. the only thing i really can solve with matrices is using the reduced row echlon (rref) when but even then i would have to know the coefficients because that only solves for x and y right? i dont understand how using matrices would help, can you explain it?

great that you are familiar with rref

look at this post --> http://www.ibsurviva...dpost&pid=99521

the context might be different but basically it's asking for the same thing.

Thank you so much, im working on the matrices for this data right now, your really helping me out. However later on, the question also asks that i should find another function that models to the data? in your opinion, whats another function besides quartic since thats the one i used, and how may i find it?

Desy,

I just wanted to thank you for putting that site up. It's really helped me, and I wouldn't be anywhere if it hadn't been for you. Thank you.

[aaaaa5]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

[deraksan]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

Logger Pro helped me a lot you can plot all of the individual data points and then create a line of best fit on the same axes for any sort of graph you want plus it gives you the parameters for whichever equation you chose.

[aaaaa5]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

Logger Pro helped me a lot you can plot all of the individual data points and then create a line of best fit on the same axes for any sort of graph you want plus it gives you the parameters for whichever equation you chose.

Really? Thanks It's an expensive program, so I'll just download the trial version and see if it solves my problem Tbh I don't know why GeoGebra can't do it - it gives me a "best fit" equation that is hardly a best fit (I found that could come up with a better one by randomly changing parameters...so something must be wrong with it :/ too bad, I really liked the program...)

[deraksan]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

Logger Pro helped me a lot you can plot all of the individual data points and then create a line of best fit on the same axes for any sort of graph you want plus it gives you the parameters for whichever equation you chose.

Really? Thanks It's an expensive program, so I'll just download the trial version and see if it solves my problem Tbh I don't know why GeoGebra can't do it - it gives me a "best fit" equation that is hardly a best fit (I found that could come up with a better one by randomly changing parameters...so something must be wrong with it :/ too bad, I really liked the program...)

Yeah don't worry about it I just hope everything works for your sake I hate portfolios. Is it? I didn't know because the program is installed on our school computers. Anyway if it does work it really was worth it for me because that's the only program I had to use. If you find that the line of best fit it comes up with could look better, you can play around with the different parameters while keeping up with the visual changed on the graph all in the same place. It really is great and I hope it helps. Good luck!

[aaaaa5]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

Logger Pro helped me a lot you can plot all of the individual data points and then create a line of best fit on the same axes for any sort of graph you want plus it gives you the parameters for whichever equation you chose.

Really? Thanks It's an expensive program, so I'll just download the trial version and see if it solves my problem Tbh I don't know why GeoGebra can't do it - it gives me a "best fit" equation that is hardly a best fit (I found that could come up with a better one by randomly changing parameters...so something must be wrong with it :/ too bad, I really liked the program...)

Yeah don't worry about it I just hope everything works for your sake I hate portfolios. Is it? I didn't know because the program is installed on our school computers. Anyway if it does work it really was worth it for me because that's the only program I had to use. If you find that the line of best fit it comes up with could look better, you can play around with the different parameters while keeping up with the visual changed on the graph all in the same place. It really is great and I hope it helps. Good luck!

Thanks It's working! But do you, by any chance, know how to change the line thickness so that it's a little bit thicker? I couldn't find a way to do it when I googled it :/

[deraksan]

Desy,

First of all, your previous posts in this thread really helped me a lot, so thank you for writing all that

But I still have a question: could you please recommend a program (other than GeoGebra, which doesn't work :/, and Autograph, which apparently can do only linear and nth degree polynomials) that could come up with a best-fit logistic function? I wanted to do a logistic function for the "using technology" part, but can't, because no program will give me a function that actually models the data (i.e. all the functions I obtained in GeoGebra just keep increasing indefinetely and don't level off at a limit - tbh I don't really know how to make the function bounded above in GeoGebra so I wondered if you knew how to get around this problem). I know that I could just pick another function, but I really wanted to try the logistic one because it looks like it could actually be a really good model if I could make it level off at a specified y-value.

Logger Pro helped me a lot you can plot all of the individual data points and then create a line of best fit on the same axes for any sort of graph you want plus it gives you the parameters for whichever equation you chose.

Really? Thanks It's an expensive program, so I'll just download the trial version and see if it solves my problem Tbh I don't know why GeoGebra can't do it - it gives me a "best fit" equation that is hardly a best fit (I found that could come up with a better one by randomly changing parameters...so something must be wrong with it :/ too bad, I really liked the program...)

Yeah don't worry about it I just hope everything works for your sake I hate portfolios. Is it? I didn't know because the program is installed on our school computers. Anyway if it does work it really was worth it for me because that's the only program I had to use. If you find that the line of best fit it comes up with could look better, you can play around with the different parameters while keeping up with the visual changed on the graph all in the same place. It really is great and I hope it helps. Good luck!

Thanks It's working! But do you, by any chance, know how to change the line thickness so that it's a little bit thicker? I couldn't find a way to do it when I googled it :/

Sorry I'm not sure but you can make the line more visible by not connecting the dots between the original data points. You just right click on the graph, click "graph options" and there un-tick "connect points" (to make the points visible you may want to tick "point protectors"). You can also make the line of best fit by zooming in and the best way to do that is to click on the button between the calculator button and the zoom in button, under the "page" tab. Hope this helps!

[aaaaa5]

Thank you anyway The logistic function I got is really great, I mean, obviously it doesn't go through all the points, but this data set is so random that I don't think it's even meant to. It's definetely better than the one I got from GeoGebra or from my GDC (though idk why... I always thought my TI was the smartest little thing out there ). As for the line thickness, I don't think it's a problem, I'll just make the graphs larger than I wanted to initially and it's going to be OK Thanks again!

[Justina]

Hey, could anyone advise, what could be written in the introduction part? I already stated the aim of my invstigation and presented one unknown function that was not taught in school, but I am not sure what could I insert more.

[aaaaa5]

Hey, could anyone advise, what could be written in the introduction part? I already stated the aim of my invstigation and presented one unknown function that was not taught in school, but I am not sure what could I insert more.

maybe some general info about the Olympics/men's high jump discipline? Like since when the Olympics are held, etc. I plan to write 2-3 such opening sentences, more is not required imho.

[hehe_lalalala]

I want to use a sine function for this, but I'm not sure how to use matrices to solve it..we never learned about augmented matrices or anything, just the basics. I feel like sine is the way to go, please help!

[swedetrader]

Hey everyone!

I've read through basically all the post and it's given me a lot of help

I was wondering what would be the best way to re-write the table using "smaller integers" for the years? A lot of people have brought it up and some have used 1,2,3,4 etc, and others 1,4,8 etc.

I'm sure all are fine but which one makes translating them back into their real values less of a hassle?

Many thanks!

[aaaaa5]

I want to use a sine function for this, but I'm not sure how to use matrices to solve it..we never learned about augmented matrices or anything, just the basics. I feel like sine is the way to go, please help!

I don't think you have to use matrices to solve for sine (and tbh I don't think you can - but you shouldn't believe me, because I'm not a mathematical genius, just trying to help ). I think that you should use the template sine equation AsinB(x-C)+D and use the rules you have learned to solve for these coefficients using the maximum/minimum points of the data set, etc.

[mistahazn]

I just have a few questions; I'm not sure what type of equation to use, because:

linear - would mean that height could be negative

exponential/logarithmic - would mean humans used to be midgets (no offense) back in the past

or, should we only look at the graph in regards to the given data set?

[uusinjsh]

Is it fine that i use something as simplistic as squareroot function (a+b*sqrt(x+c) ) ?? as long as i explain everything

[aaaaa5]

Um, I know this question might sound stupid provided that the assessment criteria are available in the Internet, but I have read them several times and am not sure about the use of so-called "calculator" notation. It's fine as long as it's not part of word-processed text, right? As in, on graphs and calculator screenshots? I'm only asking because the two IB math teachers I've asked gave mutually exclusive answers (one was like "noooo, don't ever use it", and the other said it was fine as long as it's not part of the text).

Also, what exactly is meant by "parameters"? I have defined the constraints and variables, but can anyone explain what they want from me when they ask me to define "parameters"? Sorry, I'm probably spamming by asking these questions, but it wasn't explained to us properly and the portfolio is due tomorrow :/

Edited February 20, 2012 by aaaaa5

[aaaaa5]

Is it fine that i use something as simplistic as squareroot function (a+b*sqrt(x+c) ) ?? as long as i explain everything

Sure it is, you can use any function you like provided that you explain it all in a way that makes sense And personally I think using the square root is a great idea.

[qhua]

hey guys/girls! i have to do this type two portfolio and its due in a week but i have no idea what to do! well i kinda thought it should be a piecewise function but i have no idea how to create a sine function analytically. help!!! please!!!

[opus92fan]

Is it possible for regression to create a function that is even worse than the one found analytically? That's what happened to me.

[uusinjsh]

If both manually derived and Logger Pro formula don't work for the additional data given in the second part of the task, it's ok, if i explain why (manually derived one has problems with domain, the Logger Pro - with the fact that the height in 1980 is so comparatively high) ?