IA (HL) Portfolio Type I -- How Many Pieces

[ZiggyM]

BlancheBunny103 - Try having a read through the thread - I'm pretty sure it covers that somewhere in it. But S is the formula you got for the line (section before the circle) and from memory yes that is R, however I did this a while ago now.

[BlancheBunny103]

Ah I got it now

By the way I'm on 3D. And I'm using Google Sketchup, with 3 cuts I can only get 7 pieces. Here's how I cut it.

How do you cut to get 8 parts? Please attach a picture if possible. Please help asap, my IA is due in tomorrow.

Thanks so much

Edited May 31, 2011 by Austin Glau
no text speak

[BlancheBunny103]

Also, what is the recursive formula for 3D cuboid?

Any help would be much appreciated, my IA is due tmr

[Guest 1529]

Ah I got it now

Btw I'm on 3D. And I'm using Google Sketchup, with 3 cuts I can only get 7 pieces. Here's how I cut it.

How do u cut to get 8 parts? Pls attach pic if possible. Pls help asap, my IA is due in tmr.

Thanxx so much

Divide one of the sides of the cube into 4 parts (as you did for the 2D) and then, cut it on the horizontal... did I make it clear?? o.O I mean, just cut into 4 parts one side and then, intersect a plane in the horizontal to that side...

[Guest 1529]

Also, what is the recursive formula for 3D cuboid?

Any help would be much appreciated, my IA is due tmr

I cannot tell you the recursive but there are two ways of getting it:

1st - do the method of finite differentiation

2nd - plot a graph with your points and then find the best-fit polynomial for it

that's how you get your recursive

[BlancheBunny103]

Oh ok, thanks

Then how can u get 26 pieces with 5 cuts? Pls attach a pic if possible.

Thanks so much

Edited May 31, 2011 by Austin Glau
no text speak

[Guest 1529]

Oh ok, thanxx.

Then how can u get 26 pieces with 5 cuts? Pls attach a pic if possible.

Thanxx so much

I'm not actually doing this IA lol but from what I know, you have to "play" very well with the angles of your planes. Each plane has to intersect all the others.

[Itay]

Anyone has found the equation for n cuts and m dimensions? (a general ecuation)

Thanks

Don't worry, I have found it

Edited May 31, 2011 by Austin Glau
don't double post

[imbest]

hey does anyone know how to obtain 15 parts with 4 planes and 26 parts with 5 in cuboid ????? wasted a lot of time but could not get it.....

Thanks in advance..:)

hey this is regarding the IA TYPE 1 - How Many Pieces?

does anyone know how to draw a cuboid with 4 planes to get 15 parts and with 5 planes to get 26 parts???

thanks

Edited May 31, 2011 by Austin Glau
no text speak, don't double post

[ZiggyM]

Something to look out for when cutting your cuboid is that you won't be able to see all the parts as some do not have a face on the exterieur of a cuboid. They like to hide

[BojanS]

Which graphing software are you guys using?

[Guest]

Hello all!

So basically, I'm done with the portfolio, but there's one last thing I need to ask. My teacher told me the portfolio was fine but I could find another final solution involving combinations. Has anyone got any hints regarding this final formula?

Much appreciated.

[Onewhosighs]

Hey guys, I was wondering how you drew the planes inside the cube on google sketchup.

-Stumped IB student from Vancouver

[Yazmin Reyes]

i've gotten up to the 3d part and i can't seem to figure out how to get the maximum number of parts.

the question is:

A cuboid is a finite 3d object. investigate the maximum number of parts (P) that are obtained with n cut.

-Use geometry software to investigate the maximum number of parts for n=1,2,3,4,and 5.

if someone can help me with that question and tell me the max parts per n value i can easily solve the rest. thanks

for 1 you get 2

for 2 you get 4

for 3 you get 8

for 4 you get 14

for 5 you get 22

[IB_soldier]

How do you prove your general statement? I tried MI but doesn't seem to work very well unless I assume that my recursive formula is correct. I have everything else already. But How do i prove it? please help. This is due on 10th of October.

[sampas]

I have the following questions:

1. In the 3d cuboid whats the number of cuts for 4 and 5? I have managed to find 14 for 4 cuts but here it says that you can find one more...
   
2. Using combinatories how can we find a general formula?
   

Thanks a lot

[Joanna Wu]

For the 4d part, I'm kind of stuck on trying to find the recursive form, and I already did the chart in excel and everything, but I'm not sure what kind of pattern I'm looking at.......

[BLAHAHA]

I dread the thought of talking Math HL next year

Why do you have to take Math HL next year?! I don't get it..

Are you currently finding SL hard?

I'm in 11th grade taking Math SL right now, and i'm good at it. next year is HL and i have heard that it drives people towards suicide (jk

My school doesn't let us jump to Maths HL in the final yr, I studied HL this year and I dropped it, all I heard is that the option part drives people crazy

[karinaa]

I'm at the cuboid part and using the software Autograph to model the cube and the sections.

I managed to get the model for up to 3 cuts by inserting equations for planes but after that I'm lost.

Anyone using Autograph too and knows the equation you need to put in to get the correct planes after 3 cuts?

Thanks.

[Joez]

Uh. Hi. -that moment when you lurk the forums for ages and then suddenly pop up to ask questions-. Hope I'm not grave-digging.

Anyway. I was just wondering about how one should go about outlining the scope and/or the limitations for this portfolio task. It's part of the marking criteria, and frankly.. I have no idea how to.. discuss? it. There's really not much about limitations other than the general formula only fitting for real numbers...? But then again, one would most likely be able to generate a similar general formula for the complex plane anyway.

Thanks for the help in advance.

Also, getting increasingly annoyed trying to draw planes. Would I lose marks if I don't physically draw the 5th cut but rather explain how one can obtain the cut (by using a cube with 4 cuts, and showing/explaining how the 5th cut would be able to split 11 of the 15 pieces).

~