dessskris Posted November 6, 2011 Report Share Posted November 6, 2011 (edited) From the question, it stated 'plot the data points from the table on a graph. so i would suggest only one graph...I'm not conformed yet, though.you can use Excel or Geogebra...I still don't know what suitable models should I use that have similar trends...I wish someone colud help me on this... well at the very first, you present the tables and plot everything on one same graph. but then to generate the formula, you combine a number of functions. I was thinking of using sin(x)/x. but i could not figure out how can i combine the functions together? any ideas? okay so you want to use sinx/x for the whole thing or only for one section, then another function for another section, yet another function for some other section, or how? if you want to use 1 function for the whole thing, well that's it. no need to combine anything. but if you want to use several functions, you can present it with: but without the closing bracket } Hi. I just wanted to ask, the data that you are referring to, is it the data from the total mass of fish caught in the sea or is this data from the fish farms? sorry, im kinda confused :/ thanks. the first three tables on the top, in the beginning of the task. Edited November 6, 2011 by Desy Glau Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 HiI have one question....does analytically means "without using technology?"...our teacher said that, but we can not figure out how to find values for a,b,c and d without technology...Thank you... Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 HiI have one question....does analytically means "without using technology?"...our teacher said that, but we can not figure out how to find values for a,b,c and d without technology...Thank you...yep, your teacher wasn't lying.it's possible. what type of function do you want to model? Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 Hi I have one question....does analytically means "without using technology?"...our teacher said that, but we can not figure out how to find values for a,b,c and d without technology... Thank you... can you give me any hint how to find these values? thank you Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 yep I can. can you tell me what type of function you want to model first? Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 yep I can. can you tell me what type of function you want to model first? I want to model first table..where I got cubic function....using TI-84 i got values for a b c and trough cubicReg but how to find them analytically? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 ohh CUBIC. okay you should've told me that in the mean time can you refer to this first? http://www.ibsurvival.com/index.php?app=forums&module=forums§ion=findpost&pid=99521 I know it's for a different IA, but it's actually the same, just with different data. for cubic, it's just one less variable, with similar working as in that post. Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 ohh CUBIC. okay you should've told me that in the mean time can you refer to this first? http://www.ibsurviva...dpost&pid=99521 I know it's for a different IA, but it's actually the same, just with different data. for cubic, it's just one less variable, with similar working as in that post. Than you Desy...i think that i will figure out how to find a,b,c and d....now do you have hints how to find values for sine function?... Reply Link to post Share on other sites More sharing options...
dessskris Posted November 26, 2011 Report Share Posted November 26, 2011 you're welcome if you face any problem then just post here! hmmm sin is easier, right? you could guess from the period, amplitude, etc Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 I will try that later on...and if i get some troubles I will post them here...)) one more time..Thank you... Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 26, 2011 Report Share Posted November 26, 2011 you're welcome if you face any problem then just post here! hmmm sin is easier, right? you could guess from the period, amplitude, etc ok, i know how to find a,b and d...but how do I find c?? is c constant? ://// because if i write like this (y-d)/a-sin(b*x)=sin C. it is different for different values of x and y.....:/ Reply Link to post Share on other sites More sharing options...
dessskris Posted November 27, 2011 Report Share Posted November 27, 2011 what c? the general form is:y=a sin(bx+c) +dc should give its horizontal translation. Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 yes...but how to find analytically value of c? for example..d=(max+min)/2a=(max-min)/2....c= ?am i right? Reply Link to post Share on other sites More sharing options...
dessskris Posted November 27, 2011 Report Share Posted November 27, 2011 d is the vertical translation whereas c is the horizontal translation. like, for d, how far away is the midpoint (point right in the middle of the max and min points) from 0? for c, how far is the start of the graph from 0? Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 hello,how to plot these data with tech and get nice graph??with GDC it doesnt looks nice(points)when I use graphing package from Book CD, i get dots, but i cannot zoom them properly.. Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 d is the vertical translation whereas c is the horizontal translation. like, for d, how far away is the midpoint (point right in the middle of the max and min points) from 0? for c, how far is the start of the graph from 0? I do not get it....(( these formulas for a and d, are they correct? if I write that c= b*x - sin^-1((y-d)/a) is c constant? :/ Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 hey brigadirsa,what is that cubic you are talking about?why cubicreg? and when i enter data from 1980-1988 and do cubicreg for L1, L2, i get values of a,b,c,d.. what to do with them? and why using cubic thing?thanks Reply Link to post Share on other sites More sharing options...
dessskris Posted November 27, 2011 Report Share Posted November 27, 2011 Yakuza, use your GDC or if you want you can try Geogebra or Autograph (google it)brigadirsa, I don't get what you're saying at all. the formula is y=a sin(bx+c) +d where a,b,c,d are constants. so you should get numbers. Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 thanks desy, but what to do after i draw the whole function? i know, that first part is tangent function, second and third i think are sine functions..what to do after that? Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 Yakuza, use your GDC or if you want you can try Geogebra or Autograph (google it)brigadirsa, I don't get what you're saying at all. the formula is y=a sin(bx+c) +d where a,b,c,d are constants. so you should get numbers.ok desy, i get it...they are all constants...and i figured out how to find values of a,b and d analytically...but how do i find value for c without using technology...that is my problem...can you give me formula for calculating c from this function? :/Yakuza...for the period between 1980 and 1988 i used cubic function...use TI or some computer program to plot the data and use cubReg to find a,b,c and d or look at previous posts from Desy if you need to find these values analytically. 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.