thebest Posted October 7, 2011 Report Share Posted October 7, 2011 Yeah our teacher said we can't use similar triangles.Also, how should I begin writing this IA? Should I begin with a longg introduction introducing basic concepts/characteristics of a circle and triangle? (i.e., circle has radius, triangles length = radius). . . . Also, for ppl whos written this IA, how many pages were sufficient in writing this? The math is too easy, but putting this together in a good way.. I really don't know what my teacher wants. Reply Link to post Share on other sites More sharing options...
dessskris Posted October 7, 2011 Report Share Posted October 7, 2011 hell of course not. you're writing an investigation paper, not a textbook for primary school!go with one paragraph of intro and then just start with the content. for more info please check out the Maths IA Tips in the Maths forum.usually max is 25 pages (that's what my HL teacher says, not sure about SL) but I guess it should be more than 10 pages. well it depends on how many graphs&figures you have too. Reply Link to post Share on other sites More sharing options...
thebest Posted October 12, 2011 Report Share Posted October 12, 2011 Can someone help me?,,, I feel like I'm writing too much... When do I know that I've wrote enough and how concise should I be with my explanations? But my teacher also said to make it like a "beautiful math essay"... So its like im stuck between two impossible paths 1 Reply Link to post Share on other sites More sharing options...
dessskris Posted October 13, 2011 Report Share Posted October 13, 2011 I'd rather write too much than write too concisely. concise explanations sometimes don't get to the point, so you better stick with what you've written! don't remove anything Reply Link to post Share on other sites More sharing options...
thebest Posted October 14, 2011 Report Share Posted October 14, 2011 Oh okay, thank you . Also, for anyone doing this circles portfolio,,,, the portfolio assignment sheet states that P' is the "intersection of C3 and OP." But does that mean if OP' was bigger than OP, then this would not be a valid answer because it defies the definition of P' being the INTERSECTION of C3 and OP? If OP' is bigger than OP, P' is NOT located ON OP .. its located further to the right. So im wondering if this is a limitation or if this is just a bad wording in the problem? I asked my teacher but he is very reluctant to tell us anything... Reply Link to post Share on other sites More sharing options...
iHubble Posted October 14, 2011 Report Share Posted October 14, 2011 hell of course not. you're writing an investigation paper, not a textbook for primary school! go with one paragraph of intro and then just start with the content. for more info please check out the Maths IA Tips in the Maths forum. usually max is 25 pages (that's what my HL teacher says, not sure about SL) but I guess it should be more than 10 pages. well it depends on how many graphs&figures you have too. I told my GF who is in SL Math to do it with similar triangles. Well, she's pretty much screwed then... Everybody I know in SL did it with similar triangles! Nevertheless, I told her at the beginning that she could use an algebraic method with the circle equation, but she found it a bit complex for a SL Math IA. At least she's not the only one! We'll wait and see the result. Reply Link to post Share on other sites More sharing options...
dessskris Posted October 14, 2011 Report Share Posted October 14, 2011 (edited) to everyone, you guys are allowed to use similar triangles. but the first task clearly states to "Use a trigonometric approach to find OP', when OP=2, OP=3, and OP=4" you lied. or your teacher did, as they gave you a wrong task. the task says "Use an analytic approach to find OP'...". if you don't belive me download a soft copy of the task paper in the Maths SL forum, it's in a thread called Portfolio Tasks or something like that. I told my GF who is in SL Math to do it with similar triangles. Well, she's pretty much screwed then... Everybody I know in SL did it with similar triangles! Nevertheless, I told her at the beginning that she could use an algebraic method with the circle equation, but she found it a bit complex for a SL Math IA. At least she's not the only one! We'll wait and see the result. she's not, one is not required to use trigo. Edited October 14, 2011 by Desy Glau Reply Link to post Share on other sites More sharing options...
dessskris Posted October 14, 2011 Report Share Posted October 14, 2011 Oh okay, thank you . Also, for anyone doing this circles portfolio,,,, the portfolio assignment sheet states that P' is the "intersection of C3 and OP." But does that mean if OP' was bigger than OP, then this would not be a valid answer because it defies the definition of P' being the INTERSECTION of C3 and OP? If OP' is bigger than OP, P' is NOT located ON OP .. its located further to the right. So im wondering if this is a limitation or if this is just a bad wording in the problem? I asked my teacher but he is very reluctant to tell us anything... it's good that you can see this. so now think: can the circle C3 intersect the straight line coincident with OP at the right side of point P? have you tried using different radii of C1, C2, C3? did any of it resulted in the intersection point being outside the line segment OP? if P' can never be outside of OP in the first place, it's not a limitation because for all radii, P is never outside of OP. however, you might also want to discuss this and merely state the fact that P' is always inside OP. Reply Link to post Share on other sites More sharing options...
thebest Posted October 15, 2011 Report Share Posted October 15, 2011 Oh okay, thank you . Also, for anyone doing this circles portfolio,,,, the portfolio assignment sheet states that P' is the "intersection of C3 and OP." But does that mean if OP' was bigger than OP, then this would not be a valid answer because it defies the definition of P' being the INTERSECTION of C3 and OP? If OP' is bigger than OP, P' is NOT located ON OP .. its located further to the right. So im wondering if this is a limitation or if this is just a bad wording in the problem? I asked my teacher but he is very reluctant to tell us anything... it's good that you can see this. so now think: can the circle C3 intersect the straight line coincident with OP at the right side of point P? have you tried using different radii of C1, C2, C3? did any of it resulted in the intersection point being outside the line segment OP? if P' can never be outside of OP in the first place, it's not a limitation because for all radii, P is never outside of OP. however, you might also want to discuss this and merely state the fact that P' is always inside OP. No, but when r or OA = 3 or greater (but less than 4 which is the limitation) P' is OUTSIDE the line segment OP... So is that a limitation or no? Because doesnt it defy the definition of P' which says that P' is the intersection of C3 and OP... Reply Link to post Share on other sites More sharing options...
thebest Posted October 15, 2011 Report Share Posted October 15, 2011 to everyone, you guys are allowed to use similar triangles. but the first task clearly states to "Use a trigonometric approach to find OP', when OP=2, OP=3, and OP=4" you lied. or your teacher did, as they gave you a wrong task. the task says "Use an analytic approach to find OP'...". if you don't belive me download a soft copy of the task paper in the Maths SL forum, it's in a thread called Portfolio Tasks or something like that. I told my GF who is in SL Math to do it with similar triangles. Well, she's pretty much screwed then... Everybody I know in SL did it with similar triangles! Nevertheless, I told her at the beginning that she could use an algebraic method with the circle equation, but she found it a bit complex for a SL Math IA. At least she's not the only one! We'll wait and see the result. she's not, one is not required to use trigo. And nooo haha, it clearly states "trigonometric approaches" on our portfolio sheets. Reply Link to post Share on other sites More sharing options...
Iryna Posted October 15, 2011 Report Share Posted October 15, 2011 It said "analytic approach" on mine as well!When OP=3 the intersection is outside the circle and outside the OP but it is still considered an intersection with the extension of the OP, that's what my teacher said. Limitation is 4 as there is no intersection at all if OP is bigger than 4. To find the OP' you can either use cosine and sine rules or name OP' as x and P'P as 2-x and work out the general formula using cosine rule first in the OAP' triangle and then in OAP. Reply Link to post Share on other sites More sharing options...
thebest Posted October 15, 2011 Report Share Posted October 15, 2011 It said "analytic approach" on mine as well!When OP=3 the intersection is outside the circle and outside the OP but it is still considered an intersection with the extension of the OP, that's what my teacher said. Limitation is 4 as there is no intersection at all if OP is bigger than 4. To find the OP' you can either use cosine and sine rules or name OP' as x and P'P as 2-x and work out the general formula using cosine rule first in the OAP' triangle and then in OAP.But would that method neccesarily be the best way to RECOGNIZE patterns or structures for the general statement? I'm using the cosO ratio (adjacent over hypotenuse) for triangle OP'A, which is cosO = (OP'/2)/1 = OP'/2 cuz you can divide OP' by half which is the adjacent side, and the hypotenuse is OA which is always 1 for the first question. Then im plugging this in the cosine law of triangle OPA, where you can then easily solve for OP'. By doing this isnt it also easier to recognize the patterns and general statements? Reply Link to post Share on other sites More sharing options...
thebest Posted October 16, 2011 Report Share Posted October 16, 2011 For those of you who have this portfolio, when OP =2 and r = 4, is this a limitation for the value of r ? C3 does not exist when r = 4? And if so, why is this so ?.. Reply Link to post Share on other sites More sharing options...
The Filipino Limner Posted October 16, 2011 Report Share Posted October 16, 2011 (edited) Which IA, exactly?Could you post the question, and/or the diagrams, so we could help you? Edited October 16, 2011 by The Filipino Limner Reply Link to post Share on other sites More sharing options...
thebest Posted October 16, 2011 Report Share Posted October 16, 2011 Which IA, exactly?Could you post the question, and/or the diagrams, so we could help you?Uhh its the Circles portfolio. Here's the file and its on page 5. The question is "discuss the scope and/or limitations of the general statement." Reply Link to post Share on other sites More sharing options...
dessskris Posted October 16, 2011 Report Share Posted October 16, 2011 (edited) I've replied to your message.and please don't post answers in the forum. Edited October 16, 2011 by Desy Glau Reply Link to post Share on other sites More sharing options...
dessskris Posted October 22, 2011 Report Share Posted October 22, 2011 has anyone did the first step: "Let r=1. Use an analytic approach to find OP' , when OP=2 , OP=3 and OP=4"If yes, can you write the answers to check them together? Thank you NO. nobody has posted any answer here and nobody will ever do so, because it's not allowed in this forum. any lazy lad (like you, maybe) can just ask this kind of question and copy somebody's answer, hence posting answers is prohibited. only hints are allowed. @thebest, see everyone else's task says "analytical". it's just your teacher who has changed the task, which he really isn't supposed to do. Reply Link to post Share on other sites More sharing options...
infinityplus Posted December 1, 2011 Report Share Posted December 1, 2011 What technology works the best to draw the circles? Reply Link to post Share on other sites More sharing options...
infinityplus Posted December 1, 2011 Report Share Posted December 1, 2011 has anyone did the first step: "Let r=1. Use an analytic approach to find OP' , when OP=2 , OP=3 and OP=4"If yes, can you write the answers to check them together? Thank you NO. nobody has posted any answer here and nobody will ever do so, because it's not allowed in this forum. any lazy lad (like you, maybe) can just ask this kind of question and copy somebody's answer, hence posting answers is prohibited. only hints are allowed. @thebest, see everyone else's task says "analytical". it's just your teacher who has changed the task, which he really isn't supposed to do. Hey, do you know what technology works best for this circle portfolio? Reply Link to post Share on other sites More sharing options...
dessskris Posted December 2, 2011 Report Share Posted December 2, 2011 What technology works the best to draw the circles? yep, I use my TI GDC. geometry page. it's really awesome, and you can stretch the radius of a circle to see what happens if it's smaller or larger or whatever. but if you don't like TI, I suggest using Autograph. it's the best graphing software well, after Wolfram Mathematica of course but that one is too sophisticated. try Autograph alternatively there is Geogebra. 1 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.