IA (HL) Portfolio Type II -- Modelling a Functional Building

[humsa]

somebody please tell the intial stepss???

any help would be appreciated

[Simus]

Hello everyone,

by modelling do you mean creating a 3D model? How do you use geogebra to do that?

[∫ Jorge δx]

I did not use Geogebra to make the visuals for my (still incomplete) IA. All the rough visuals were made in Google Sketch-up

[Simus]

I was trying to use google sketchup too but I don't know how to create a parabolic structure. How do you do that?

[∫ Jorge δx]

Create an arc, draw a line beneath it, push-pull tool.

Hope that helps.

EDIT: It's gonna be a pain to create a 3D model in Sketch-up for the second-to-last bullet. However, it's not impossible. But I suggest to create the cuboids first, and then fit them to the arc. Also, for the math on that same part, I highly recommend to use a height of 3 for each of your floors. You will thank me later.

Edited December 4, 2010 by qliphoth93

[humsa]

Autgraph works best for any 3D function

you can download a trial version of it for 30days from http://www.autograph-math.com/download/index.shtml

I hope this will help you...

Edited December 5, 2010 by Mahuta ♥
Please do not use text speak!

[suggaplum]

Away, you are not supposed to give the answer, just guidance in how to solve the question..

Try searching up optimisation under differentiation. As for the 2xy, try thinking along the lines of the shape of the rectangle

[shadeslayer]

i just got this IA and it's due in a weeks time, has anyone done this one before.... i really need some help..

mines not the exact same, its about the population growth of the bacteria in yoghurt

[tonydaazntiger319]

alright for the first question where it says to create a model when the height is 36m, does that mean we need the 150 length and 72m width for that model? Or are those dimensions simply for the cuboid?

[Ellie17B]

I am doing this for maths at the moment. I have found that to find the values for the equation, you have a simplified equation and input the value 36 because that is the height of the curve and therefore you can find K (when using Y=-kx^2+36). Use this to find out the x value through differentiation and volia

then you can find out the area and volume from there.

I found using a spreadsheet for point 3 works well and in point 4, I found each different height gave the same ratio of wasted space to volume of the office block. Point 5 I haven't worked out what to do with it yet but I have been suggested using levels? but it seems that is more likely for point 7. Point 6 is easy you just have to do points 1 and 2 again using the different values. Hope this helps

[Rory Rendall-Tyrrell]

Advice for point 2?

it's an odden'

[∫ Jorge δx]

For point 2, find the derivative of your volume function, then set it to equal to zero and solve. Input the x value you get into your function...

Ta da! You the volume of the biggest possible cuboid!

[Morpheus]

Is everyone using y=x^2 parabola like equations for the building or are you going to use different shapes/equations?

[RBST]

Some are using an ellipse as the shape. But I personally don't think that the building looks like half an ellipse.

[∫ Jorge δx]

You can make it a half circle. If you look at your initial dimensions at minimum height, it's almost as if there were a radius.

However, I recommend against it, since it's going to make your life slightly harder if you choose to work with a half-circle later on throughout the process.

Then again, it's all open to interpretation. I saw some of my friends' IAs on the same topic, and we interpreted several parts of the prompt differently.

[Morpheus]

For point 2, find the derivative of your volume function, then set it to equal to zero and solve. Input the x value you get into your function...

Ta da! You the volume of the biggest possible cuboid!

how dare you use "ta dah" in relation to this piece of rubbish haha

By the way, just so you know, you can graph the hell out of this portfolio it helps

ALSO

Thank you guys NIce to know that we are all on the right track HL MATHS FOR LIFE!!!

Edited December 17, 2010 by Mahuta ♥
No CAPS and no need for all those smiley's -Thanks

[Ben92]

Hi

I'm also doing this portfolio. I have an issue with the assessment criteria, namely criterion C and D. In criterion C , to be award a level 5/5 it says :"The student applies the model to other situations". In criterion D, again to award full marks it says":The student has correctly and critically interpreted the reasonableness of the results of he model in the context of the task, to include possible limitations and modifications of the results, to the appropriate degree of accuracy".

I don't know how to do that in this task. Especially applying the model to other situations. Any suggestions are appreciated, thanks

[IB_soldier]

When you say the volume function..... do you mean the volume function of the whole building or the volume function of the cuboid only?

[Morpheus]

When you say the volume function..... do you mean the volume function of the whole building or the volume function of the cuboid only?

Do the volume of a cross section. The Building is a prism.

[IB_soldier]

I know the volume of the whole building, but how do i obtain the volume equation of the cuboid? How do I obtain the height of the cuboid?