Lend a helping hand (1 Viewer)

[pals_2005]

No arrogance intended... i am posting to offer a place for people to puit problems with their maths, on any topic other than mechanics (ill try harder 3u)... why do i do this.. cauz im a nice guy and in the words of some guy: you learn the most when u teach...

 

[lfc_reds2003]

why would u post such a thread when the whole idea of BOS is to exchange help

 

[pals_2005]

becasue i am a nice guy... all i am offering is help if u dont want it dont post its pretty simple...

 

[KFunk]

Why not mechanics?

 

[lfc_reds2003]

hasnt done it yet at school and we dun teach ourselves
... think about it ....

 

[pals_2005]

although its an option to teach ourselves, i really cant be bothered... but ask me anything else

 

[3.1415926535897]

excuse Mr pals... ive got a question that ive been struggling with all night..

on volumes

thanks for the help





THE QUESTION IS:

The base of a particular solid is X^2 + Y^2 = 4. Find the volume of the solid if every cross section perpendicular to the X-axis is a parabolic segment with axis of symmetry passing throught the X-axis and height the length of its base.

(Arnold+Arnold - what a beautiful love child they vhave - Ex.6.3 q 7)

 

[shafqat]

i though you only needed 5 minutes?

 

[FinalFantasy]

excuse Mr pals... ive got a question that ive been struggling with all night..

on volumes

thanks for the help





THE QUESTION IS:

The base of a particular solid is X^2 + Y^2 = 4. Find the volume of the solid if every cross section perpendicular to the X-axis is a parabolic segment with axis of symmetry passing throught the X-axis and height the length of its base.

(Arnold+Arnold - what a beautiful love child they vhave - Ex.6.3 q 7)

A of dat segment=8y²\3 after using simpsons
volume is delta-v=8y²\3 delta-x
=8\3(4-x²) delta-x
V=int. that from -2 to 2

 

[KFunk]

THE QUESTION IS:

The base of a particular solid is X^2 + Y^2 = 4. Find the volume of the solid if every cross section perpendicular to the X-axis is a parabolic segment with axis of symmetry passing throught the X-axis and height the length of its base.

(Arnold+Arnold - what a beautiful love child they vhave - Ex.6.3 q 7)

Using simpsons and integrating a parabola in the form y= -4x(x-a)/a i got the area of such a parabola as being 2a²/3

Since x² + y² = 4 the base length of a cross section of any given x coordinate is a=2√(4 - x²)

using the area of the parabolic section found above we get:

δV = 2a²/3 = 8/3(4 - x²) δx

V = lim (&deltax --> 0) 8/3 ∑ (4 - x²) δx (-2 --> 2)
= 8/3 ∫ 4 - x² dx (-2 -->2)
= 8/3[ 4x - x³/3] (-2 -->2)
= 8/3[10 2/3] = 256/9 units³

 

[HayleeKate]

No arrogance intended... i am posting to offer a place for people to puit problems with their maths, on any topic other than mechanics (ill try harder 3u)... why do i do this.. cauz im a nice guy and in the words of some guy: you learn the most when u teach...

May I offer this also as a place to aid your english abilities pals? No arrogance intended, I'm simply a nice girl.
What you should have written is:
...a place for people to PUT problems...
...Why do I do this?... BECAUSE... [although technically you should not start your sentence with the word because]

 

[dawso]

May I offer this also as a place to aid your english abilities pals? No arrogance intended, I'm simply a nice girl.
What you should have written is:
...a place for people to PUT problems...
...Why do I do this?... BECAUSE... [although technically you should not start your sentence with the word because]

nice...........

 

[KFunk]

English Schminglish. All grammar/spelling police should consult the origin of my avatar .

 

[3.1415926535897]

sorry i guess u havent heard of the 'TYPO'
since i'm such a nice guy, ill introduce it to you... it's when ones finger slips and thus the wrong letter is registered...

Haylee, u must be feeling insecure if u want to bag ppl for grammar mistakes in a MATHS thread... think about it....

Mr pals is just a nice guy so leave him alone

 

[lfc_reds2003]

excuse me PI, this is my bos gf (or was??) ur talking about... so if u want some trouble, then by all means continue.. but messing with me is dangerous..

muahahahahaha

 

[lfc_reds2003]

oi dawso mate.. keep out of it.. ur comment was really token

 

[lfc_reds2003]

sooooory man, just a bit of fun to brighten up these boring maths threads....

 

[redruM]

English Schminglish. All grammar/spelling police should consult the origin of my avatar .

should be YOU ARE*

(sorry couldnt help )

 

[lfc_reds2003]

it's ironic (his avatar that is)

 

[HayleeKate]

Sorry Steele, you're correct. We should leave our personal issues off the forum. However, I dislike the way many feel that as they are brilliant mathematicians, that excuses them from correct usage of the english language. I was genuinely doing pals a favour, english is the compulsory subject after all.

Sorry pals, I'm sure you're a great bloke, and I may well turn to you for help one day. [although I have aural sax my 'bos bf' (we're official, are we?)]