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C2: Application of Differentiation Again

image.jpg

Q: This diagram represents a rectangular sheet of metal 8 cm by 5 cm. Equal squares of side x cm are removed from each corner, and the edges are then turned up to make an open box of volume v cm^3. Show that v = 40x - 26x^2 + 4x^3
Hence find the maximum possible volume, and the corresponding value of x.

Help would really be appreciated
(edited 8 years ago)

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Original post by TarotOfMagic
image.jpg


huh? :confused:
Original post by TarotOfMagic
image.jpg

Q: This diagram represents a rectangular sheet of metal 8 cm by 5 cm. Equal squares of side x cm are removed from each corner, and the edges are then turned up to make an open box of volume v cm^3. Show that v = 40x - 26x^2 + 4x^3
Hence find the maximum possible volume, and the corresponding value of x.

Help would really be appreciated


For the first bit, can you see that the lengths of the sides will now be 8-2x and 5-2x? Then the height will be x. Multiplying these together will give you the volume :smile:
Original post by TarotOfMagic
image.jpg

Q: This diagram represents a rectangular sheet of metal 8 cm by 5 cm. Equal squares of side x cm are removed from each corner, and the edges are then turned up to make an open box of volume v cm^3. Show that v = 40x - 26x^2 + 4x^3
Hence find the maximum possible volume, and the corresponding value of x.

Help would really be appreciated


wow what a question

did you try draw the net? is it possible for you to post an attempt?

Edit: too slow
Original post by DylanJ42
huh? :confused:


Sorry, I accidently submitted it without writing the question: I have edited it now.
Original post by TarotOfMagic
Sorry, I accidently submitted it without writing the question: I have edited it now.


how are you getting on with it?
Original post by tinkerbella~
For the first bit, can you see that the lengths of the sides will now be 8-2x and 5-2x? Then the height will be x. Multiplying these together will give you the volume :smile:


Thanks so much! I have solved the question correctly. :smile:
Original post by TarotOfMagic
Thanks so much! I have solved the question correctly. :smile:


Awesome! No problem :h:
Reply 8
Avatar for Zacken
Zacken
22
Original post by tinkerbella~
Awesome! No problem :h:


Are you the maths fairy
Original post by Zacken
Are you the maths fairy


No that's you dear
Reply 10
Avatar for Zacken
Zacken
22
Original post by tinkerbella~
No that's you dear


I am the maths fairy
Original post by Zacken
I am the maths fairy


If I leave math questions under my pillow, do I get money?


Posted from TSR Mobile
Reply 12
Avatar for Zacken
Zacken
22
Original post by drandy76
If I leave math questions under my pillow, do I get money?


Posted from TSR Mobile


You get £eiπe^{i\pi} for every maths problem. :wink:
Original post by Zacken
You get £eiπe^{i\pi} for every maths problem. :wink:


How does one get negative money :confused:?
Reply 14
Avatar for Zacken
Zacken
22
Original post by zetamcfc
How does one get negative money :confused:?


I'd be stealing it from him, that was the point. Vector quantity and all. :tongue:
Original post by zetamcfc
How does one get negative money :confused:?


well you could go to a £9000 a year uni to learn maths for a start :laugh:

Edit: missed the joke too
(edited 8 years ago)
Original post by Zacken
I'd be stealing it from him, that was the point. Vector quantity and all. :tongue:


I see... getting quite late... brain not working well...
Original post by drandy76
If I leave math questions under my pillow, do I get money?


Posted from TSR Mobile


if you leave money under your pillow you get a maths problem :wink:
Original post by Zacken
I'd be stealing it from him, that was the point. Vector quantity and all. :tongue:


My money is kept in 5 dimensional space, your 3rd dimensional translations have no chance


Posted from TSR Mobile
Original post by DylanJ42
well you could go to a £9000 a year uni to learn maths for a start :laugh:


I have.......:cry:

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