Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 ok, and when i find a general formula for 1980-1988 with a,b,c,d which i found, do i have to do the sinreg now for the rest of function? if i get the other function, what do to next, in order to make a " final" model Reply Link to post Share on other sites More sharing options...
dessskris Posted November 27, 2011 Report Share Posted November 27, 2011 Yakuza, then you can start modelling a function.brigadirsa, I'm not sure if there's such formula I could think of, but look at the point where the graph starts, its x coordinate. for example if the original sin graph is translated horizontally by 3 units to the right, c=-3 Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 and maybe i sound stupid now, but how to model function? what does modelling means? Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 Yakuza, then you can start modelling a function. brigadirsa, I'm not sure if there's such formula I could think of, but look at the point where the graph starts, its x coordinate. for example if the original sin graph is translated horizontally by 3 units to the right, c=-3 ok...thanks a lot and sorry for interrupting you... Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 and maybe i sound stupid now, but how to model function? what does modelling means?when you find correct functions and parameters (a,b,c and d) you have to find best fit curve first using technology then analytically... Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 and this is what i got when i did cubreg for years 1980-1988.. is this possible?http://imageshack.us/photo/my-images/545/pokit3416a75f4cea910950a.jpg/ Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 yep....i got same...and if you plot this line on graph you will see that it is best fit curve... Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 oh, thank you very much now i have to do the same thing but sinreg for the next table? 1989-1997? and what regression to use for the last part? Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 yep but be careful because they want to find these values analytically...without technology...and for the last one i think it is cosine function...but im not sure... Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 i have used sin regression and for the last one.. but how to do it analytically?? Reply Link to post Share on other sites More sharing options...
Yakuza Posted November 27, 2011 Report Share Posted November 27, 2011 and how to draw again the function with the geenral formula for for example first part(tangent part) Reply Link to post Share on other sites More sharing options...
brigadirsa Posted November 27, 2011 Report Share Posted November 27, 2011 i have used sin regression and for the last one..but how to do it analytically??you have to find a,b,c and d using period ,amplitude and etc....the last question I do not understand very much...you are talking about whole period between 1980 to 2006? or what? honestly i did not use tangent function in this IA... :/ 1 Reply Link to post Share on other sites More sharing options...
AdnaH Posted November 27, 2011 Report Share Posted November 27, 2011 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. Can you tell me if it is enough to do only regression using a calculator for analiticaly developing part? For example, when for each table regression is separately done and combined in a model, is it fine enough? Reply Link to post Share on other sites More sharing options...
gewgle Posted November 28, 2011 Report Share Posted November 28, 2011 (edited) On the second part where it says "plot the data points from this table on a graph, and discuss whether your analytical model for the original data first the new data."Are the referring to the first set of data we developed an analytical model (the fish caught in sea) for or are we supposed to create an analytical model for the new set of data (the fish farms) too.I'm assuming original data equates to the sea fish, because it is referred to that later on? Edited November 28, 2011 by gewgle Reply Link to post Share on other sites More sharing options...
dessskris Posted November 29, 2011 Report Share Posted November 29, 2011 Can you tell me if it is enough to do only regression using a calculator for analiticaly developing part? For example, when for each table regression is separately done and combined in a model, is it fine enough?NO. analytical means algebraic, mathematical. need to show working. do NOT use regression from calculator in your first model. unless you want to lord marks.On the second part where it says "plot the data points from this table on a graph, and discuss whether your analytical model for the original data first the new data."Are the referring to the first set of data we developed an analytical model (the fish caught in sea) for or are we supposed to create an analytical model for the new set of data (the fish farms) too.I'm assuming original data equates to the sea fish, because it is referred to that later on?okay a quick rough outline:- they ask you to model analytically a function for the first 3 tables- they ask you to model technologically a function for the first 3 tables- they ask you to modify any of the two functions you've previously modelled to fit the data for the last 3 tablesso, the answer to your question is: they're referring to the model you've previously created for the first set of data. Reply Link to post Share on other sites More sharing options...
AndAMinorInHistory Posted December 14, 2011 Report Share Posted December 14, 2011 Thanks for the help! Reply Link to post Share on other sites More sharing options...
Glacierfreeze Posted December 16, 2011 Report Share Posted December 16, 2011 what about fish farm? what kinds of models do you guys think might be suitable? i can only think of using linear, quadratic and cubic or quartic for the whole thing. Maybe tan graph??Is there any software besides geogebra? there is no cos nor tan option in geogebra. My GDC also doesn't have those options. Reply Link to post Share on other sites More sharing options...
ibstudentneedshelp Posted December 21, 2011 Report Share Posted December 21, 2011 i got my maths sl type 2 portfolio. the fish production. i am trying to understand what to do, but cannot come up with any solution. i need some help please Reply Link to post Share on other sites More sharing options...
aarti Posted January 2, 2012 Report Share Posted January 2, 2012 Does anybody have the assessment criteria for this portfolio? Reply Link to post Share on other sites More sharing options...
Not Cliche Posted January 8, 2012 Report Share Posted January 8, 2012 (edited) If anyone out there is still working on this/finished, could you please confirm or answer as much as you can about the following?1. The trend of the fish farms plot seems to be following that of an exponential function (despite the fluctuation towards the end).2. The generally decreasing trend of fish-catching in the sea is explained by the rise in fish farming.3. ??? The fish production from the sea will continue to decrease (general trend) while the fish production from fish farms will continue to increase - however, only up until a certain point for both as fish farms are limited in the quantity of fish they can produce. ??? - Not so sure on this one.Any thoughts?(Sorry, I know this sounds too demanding for someone who's asking for help, but I promise to pay back the community some day..!)...awks Edited January 8, 2012 by Not Cliche 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.