ibmalkA Posted October 27, 2011 Report Share Posted October 27, 2011 Hi,We just got this IA today, and our teacher told us that parameters were unknowns that we would find in our investigation. For example, in a quadratic equation, y = a(x-h)+ kthe variables are x and ybut the parameters are a, h, and kHopefully that helps? 2 Reply Link to post Share on other sites More sharing options...
URA BOAT Posted October 28, 2011 Report Share Posted October 28, 2011 trust me hey... I'm experienced with helping with IAs.I bet you're familiar with quadratic function too. it's y=ax^2+bx+cother types of function you can possibly model:- Cubic y=ax^3+bx^2+cx+d- Quartic y=ax^4+bx^3+cx^2+dx+e- Polynomial to nth degree y=ax^n+bx^(n-1)+cx^(n-2)+...- Power- Exponential- Logarithmic- Sin- Cos- Tan- LogisticI think there can be more, but those are the more famous ones.I'm sure you're familiar with almost all of those! you can pick from that list when modelling a function analytically.i'm useing Polynomial to nth degree y=ax^n+bx^(n-1)+cx^(n-2)+... one but idk what a,b,c would be...i mean how do they relate to the data..? Reply Link to post Share on other sites More sharing options...
dessskris Posted October 28, 2011 Report Share Posted October 28, 2011 i'm useing Polynomial to nth degree y=ax^n+bx^(n-1)+cx^(n-2)+... one but idk what a,b,c would be...i mean how do they relate to the data..? for n= what? you can only choose one value of n the a b c are the parameters. they are not directly related to the data, but they are related in a sense that they control the shape of the curve that models the data. if you meant to ask how to find them from the data, you should use matrices. remember how you solve simultaneous equations in 2x2 matrices? it should be similar Reply Link to post Share on other sites More sharing options...
Guest Humaira Posted October 28, 2011 Report Share Posted October 28, 2011 I don't understand how to take the data, to create an equation.also I started the Ib diploma program year 1 in September so we haven't done matrices, vectors or stats probability yet. Reply Link to post Share on other sites More sharing options...
dessskris Posted October 28, 2011 Report Share Posted October 28, 2011 kill your teacher for telling you to do an IA with no background knowledge or such.which task is this anyway? 1 Reply Link to post Share on other sites More sharing options...
Guest Humaira Posted October 31, 2011 Report Share Posted October 31, 2011 kill your teacher for telling you to do an IA with no background knowledge or such.which task is this anyway?The gold medal heights task 2 Reply Link to post Share on other sites More sharing options...
dessskris Posted November 1, 2011 Report Share Posted November 1, 2011 kill your teacher for telling you to do an IA with no background knowledge or such. which task is this anyway? The gold medal heights task 2 umm is there anything you want to ask? for how to find a model, click here --> I know it's from a different task, but all the Maths SL type 2 tasks are basically asking for the exact same thing, just that each task has different data to analyse. any question you can ask here. Reply Link to post Share on other sites More sharing options...
Guest Humaira Posted November 1, 2011 Report Share Posted November 1, 2011 kill your teacher for telling you to do an IA with no background knowledge or such. which task is this anyway? The gold medal heights task 2 umm is there anything you want to ask? for how to find a model, click here --> I know it's from a different task, but all the Maths SL type 2 tasks are basically asking for the exact same thing, just that each task has different data to analyse. any question you can ask here. i am using a quadratic equation to represent the data? do you think this is a good choice? so then i could find the equation of y=ax^2+bx+c by taking the vertex of the parabola?if i did this i would have to sub in negative x values(negative years in this case) then find a and b? or is there another way? Reply Link to post Share on other sites More sharing options...
Guest Humaira Posted November 2, 2011 Report Share Posted November 2, 2011 kill your teacher for telling you to do an IA with no background knowledge or such. which task is this anyway? The gold medal heights task 2 umm is there anything you want to ask? for how to find a model, click here --> I know it's from a different task, but all the Maths SL type 2 tasks are basically asking for the exact same thing, just that each task has different data to analyse. any question you can ask here. i am using a quadratic equation to represent the data? do you think this is a good choice? the data is so complicated!!! how do you find a quadratic equation algebraically? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 2, 2011 Report Share Posted November 2, 2011 sorry I took so long to reply. hmmm I can't tell whether it's a good model, but if you think that's the best thing you could do then there you go. as long as you can write well, that shouldn't be too much of a problem. to model a quadratic graph, I thought you'd know already? you have more than 3 data points, what should you do?hint: you can use matrices. refer back to the general form y=ax^2+bx+c Reply Link to post Share on other sites More sharing options...
URA BOAT Posted November 18, 2011 Report Share Posted November 18, 2011 wow...ths one is not that hard...i use http://www.geogebra.org/webstart/geogebra.htmlall you have to do is add a spreadsheet...put the data in make a graph...pick what kind of formula you what to use...Logistic is what i used...then continue to the next question!!! Reply Link to post Share on other sites More sharing options...
vivesta Posted November 19, 2011 Report Share Posted November 19, 2011 (edited) When i'm creating a table of all the results I was told not to do the year column as 1932, 1936 etc but as year 1, 4,8 which is the number of years after the first given year... i was wondering how to label the first row... help? I have it as 141216etc Edited November 19, 2011 by vivesta Reply Link to post Share on other sites More sharing options...
URA BOAT Posted November 19, 2011 Report Share Posted November 19, 2011 i don't see why you would plot it that way. well unless if you are trying to show the relationship in the years that were give. i mean if you really feel that that's how you what to do it go ahead. but i personally disagree i would just plot the year vs. the height or vise versa idk...if you going to plot it in your way you can label it as "years from 1932" Reply Link to post Share on other sites More sharing options...
dessskris Posted November 19, 2011 Report Share Posted November 19, 2011 sometimes when you model a function you'll need to convert the data into smaller variables yes but you still present the data as real years. you may then introduce a new variable for the smaller year values, and use this to model your function, but don't forget to substitute back the real year values so when you plot it, it'll fit the real data. Reply Link to post Share on other sites More sharing options...
vivesta Posted November 19, 2011 Report Share Posted November 19, 2011 i don't see why you would plot it that way. well unless if you are trying to show the relationship in the years that were give. i mean if you really feel that that's how you what to do it go ahead. but i personally disagree i would just plot the year vs. the height or vise versa idk... if you going to plot it in your way you can label it as "years from 1932" I was really confused to why the teacher told us to plot it that way as well because if i don't take the advice from the teacher, i could get marked down in the end because she is the one marking it... thanks though Reply Link to post Share on other sites More sharing options...
dessskris Posted November 20, 2011 Report Share Posted November 20, 2011 i don't see why you would plot it that way. well unless if you are trying to show the relationship in the years that were give. i mean if you really feel that that's how you what to do it go ahead. but i personally disagree i would just plot the year vs. the height or vise versa idk... if you going to plot it in your way you can label it as "years from 1932" I was really confused to why the teacher told us to plot it that way as well because if i don't take the advice from the teacher, i could get marked down in the end because she is the one marking it... thanks though hey you DO need to do it. your teacher is right. sometimes when you model a function you'll need to convert the data into smaller variables yes but you still present the data as real years. you may then introduce a new variable for the smaller year values, and use this to model your function, but don't forget to substitute back the real year values so when you plot it, it'll fit the real data. Reply Link to post Share on other sites More sharing options...
baddestwoman Posted November 20, 2011 Report Share Posted November 20, 2011 still so confused about this SL, i've read all these posts like multiple times and no help. Alright so i plotted the data on a graph and i'm deciding to go with quartic function, what now? how do i make an equation related to this data? im just looking for a,b,c,d and e right? how do i do this?! Reply Link to post Share on other sites More sharing options...
dessskris Posted November 20, 2011 Report Share Posted November 20, 2011 still so confused about this SL, i've read all these posts like multiple times and no help. Alright so i plotted the data on a graph and i'm deciding to go with quartic function, what now? how do i make an equation related to this data? im just looking for a,b,c,d and e right? how do i do this?!use matrices. Reply Link to post Share on other sites More sharing options...
baddestwoman Posted November 20, 2011 Report Share Posted November 20, 2011 still so confused about this SL, i've read all these posts like multiple times and no help. Alright so i plotted the data on a graph and i'm deciding to go with quartic function, what now? how do i make an equation related to this data? im just looking for a,b,c,d and e right? how do i do this?!use matrices.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? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 20, 2011 Report Share Posted November 20, 2011 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.ibsurvival.com/index.php?app=forums&module=forums§ion=findpost&pid=99521 the context might be different but basically it's asking for the same thing. 1 Reply Link to post Share on other sites More sharing options...
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