View Full Version : What is formula pi * are 2 * h / 3,363?
abver
Dec 9, 2010, 04:00 AM
Unknown008
Dec 9, 2010, 06:18 AM
I don't see what you are referring to... the closest formula is the formula for the volume of a cylinder:
Volume\ of\ cylinder= \pi r^2h
abver
Dec 9, 2010, 07:07 AM
No is not
Unknown008
Dec 9, 2010, 07:11 AM
Where did you get that 'formula'?
abver
Dec 9, 2010, 07:19 AM
Is volume formula, not for cylinder
Unknown008
Dec 9, 2010, 07:25 AM
Um... what language do you speak?
abver
Dec 9, 2010, 07:28 AM
I'm serb
Unknown008
Dec 9, 2010, 07:33 AM
Видим...
Ја још увек не знам где сте добили ову формулу, али то је формула за запремине цилиндра, подељен 3363 коју ја не знам где сте добили.
Могу ли питати за оно питање које сте добили од те формуле? Будете могли да шаљете целу питање да ли је могуће?
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I see...
I still don't know where you got this formula, but it is the formula for the volume of a cylinder, divided by 3363 which I don't know where you got.
Could I ask in what question you got that formula from? Can you post the entire question if possible?
abver
Dec 9, 2010, 07:43 AM
Pa Srbi su pametan narod I to nije formula za zapreminu cilindra vec za drugaciju geometrisku figuru,
Unknown008
Dec 9, 2010, 07:46 AM
Нисам рекао супротно... Ја само питам где сте добили ту формулу, или да ли имате слику фигура?
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I didn't say the opposite... I'm just asking where you got that formula, or do you have a picture of the figure?
abver
Dec 9, 2010, 08:17 AM
Koliko imas godina
Unknown008
Dec 9, 2010, 08:37 AM
И'м осамнаест. Могу ли да знам зашто?
abver
Dec 9, 2010, 08:44 AM
OK, mlad si, razumi ovo kao neki zadatak I ako mozes resi ga, srecno, vise necu davati komentare
Unknown008
Dec 9, 2010, 09:17 AM
Ок, али ја немам појма шта је око формуле. Као што сам раније рекао, најближи формула је запремина цилиндра. Што се зашто је то подељено са 3363, не знам. Можда је то због фактор конверзије...
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Ok, but I don't have a clue of what the formula is about. As I said earlier, the closest formula is the volume of a cylinder. As to why it is divided by 3363, I don't know. Maybe it's due to a conversion factor...
abver
Jan 20, 2011, 01:25 PM
2 pi 2 / ((pi 2) - 4) = 3,3629...
ebaines
Jan 21, 2011, 09:24 AM
Interesting - but can you tell us where this comes from, and why it was included in your volume formula?
\frac {2 \pi ^2} {\pi^2 - 4} = 3.3629...
ebaines
Jan 24, 2011, 03:53 PM
I've been thinking about this. Here's one possible scenario where you would get this factor in your volume equation. If you consider a parabaloid of height h and base radius R, its volume is:
V_1 = \frac 1 2 \pi h R^2
Now if that paraboloid had material removed from it in the shape of a second narrower parabaloid, also of height h but with base radius = (2/ \pi) R , the volume of material removed is:
V_2 = \frac 1 2 \pi h (\frac {2 R} {\pi})^2
So subtracting one from the other yields:
V = V_1 - V_2 = \frac 1 2 \pi h (R^2 - (\frac {2R} {\pi})^2) \\
= \pi h R^2(\frac 1 2 - \frac 4 {2 \pi ^2}) = \pi h R^2 (\frac {\pi^2 - 4} {2\pi^2}) = \pi h R^2 (\frac 1 {3.3629..})
Perhaps this is the shape you are looking for?
abver
Jan 26, 2011, 06:31 AM
No is not,l give my anwers
Unknown008
Jan 26, 2011, 08:58 AM
Did you get the corrections? If so, could you tell us what it was?
abver
Apr 19, 2011, 09:11 PM
surface area = pi * r 2 + r * pi * h for this figura
ebaines
Apr 20, 2011, 05:42 AM
surface area = pi * r 2 + r * pi * h for this figura
Sounds once again like you're talking about an open-ended cylinder, whose surface area consists of the cylinder wall plus one end cap:
A = \pi r^2 + \pi r h
And the volume would be (as Unknown008 noted, oh so long ago):
V = \pi r^2 h
So, abver, did you ever figure out where the factor 3.3629 came from in your original post?
abver
Apr 20, 2011, 09:40 PM
serb : V = pi * r ^ 2 * h / 3,3629.. A = pi * r ^ 2 + pi * r * h su obrasci koji definisu jednu geometrisku figuru ( koja nije valjak) to jest njenu zapreminu I povrsinu a pitanje je koja je to figura, I iz cega se sastoji ? (3,3629.. jnaravno da sam shvatio odakle potice, mogao bi da objasnim, al mi se ne gubi vreme) ustvari mene zanima da li su ovi obrasci poznati vrsnim ekspertima kao sto ste vi I uopste (inace meni je matematika hobi ali samo ponekad)
ebaines
Apr 21, 2011, 05:45 AM
abver's response as translated by Google:
"the patterns that define a geometric figure (not roller) that is its volume and surface area and the question is what that figure, and from what constitutes? (3.3629 .. jnaravno I figured originated, could explain, but I do not waste time) I really care whether these patterns are known excellent experts like you, and in general (who is my math is a hobby, but only sometimes)."
Wow, that's really helpful.
Unknown008
Apr 21, 2011, 09:36 AM
Indeed, this sort of hobby, I dare say is not healthy at all! D:
If at least you are deriving that formula, with meaningful equations and such, then it's okay, but here... here... I just don't see the point in that, sorry. And I don't think that anyone who has math as a hobby would like to know those patterns.
abver
Apr 21, 2011, 02:04 PM
Serb : ako mozes da razumes zasto je (opposite AB / sec) + ((opposite AB - (opposite AB / sec)) * 4/3) ~ arc AB mozda I mo nadjes poentu u gornjim jednacinama
abver
Apr 21, 2011, 02:18 PM
pod uslovom da je hipotenuza = precnik
galactus
Apr 21, 2011, 02:36 PM
Jjuiibn;j h hmnk mxvnncvuygaefnbamn
I checked Google and this "problem" has been posted on a dozen different sites. No one else appears to know what it means either.
Especially, the 3363.
abver
Apr 21, 2011, 06:41 PM
2 pi 2 / (pi 2 - 4) je formula koja daje odnos zbira povrsina svih jedinstvenih segments (pi 2 - 4) I zbira odgovarajuceg broja povrsina circle (2 pi 2), odnosno volume of a cylinder I volume geometriskog tela koja se sastoji od povrsina svih jedinstvenih segments a taj odnos je 3,3629.. a odgovor je (diameter * 1/2 chord A) / 2 = triangle A ;; dakle (r 2 * pi / 2 ) - triangle = area of a two segments ;; dakle triangle A / chord A = x ;; dakle (r 2 * pi / 2) / x = diameter * 1/2 pi ;; dakle ((diameter * 1/2 pi) - chord A) * x = (r 2 * pi / 2) - triangle A = area of a two segments;; dakle zbir svih jedinstvenih chords je RADIUS a zbir odgovarajuceg broja diameters je (2 r * pi) / 4 ;; dakle ((2 r * pi) / 4 * 1/2 pi - r) * x = zbir povrsina svih jedinstvenih segments a zbir odgovarajuceg broja povrsina circle je ((2 r * pi) / 4 * 1/2 pi * 2) * x ;; dakle (2 r * pi / 4 * pi) / (2 r * pi / 4 * 1/2 pi - r) ova formula moze da se svede na 2 pi 2 / (pi 2 - 4)
Unknown008
Apr 22, 2011, 08:55 AM
Okay, I can't understand what you're talking about. Give me a practical example where this is used.
abver
Apr 24, 2011, 02:41 PM
OK , pokusacu da objasnim , nacrtaj cetvrtinu kruga, sada zamisli da je centralna tacka povezana poluprecnicima (radius you mnozini) sa svakom tackom na cetvrtini kruznice, na taj nacin dobio bi poluprecnike you svim uglovima od 0 do 90, sada zamisli da su svi ti poluprecnici povezani you nizu redom od vertikalnog do horizontalnog, tako da zadnja tacka jednog poluprecnika predstavlja pocetnu tacku drugog (sledeceg) poluprecnika, na taj nacin dobio bi poligon sa beskonacno stranica, sada zamisli da svaku stranicu (poluprecnik) zamenjuje tacka, na taj nacin dobio bi iskrivljenu liniju koja bi bila identicna cetvrtini kruznice. Vracamo se na pocetak, zamisli da svaki poluprecnik predstavlja hipotenuzu, you tom slucaju zbir svih stranica (opposite I adjancent) pravouglih trouglova predstavljala bi pravu does, koja bi bila jednaka poluprecniku (radius) kruga cija je cetvrtina nacrtana na pocetku, ako ovo razumes ti napisi
abver
Apr 28, 2011, 03:29 PM
Sustina je da, kada od povrsine polukruga oduzmes pravougli trougao ciji je poluprecnik jednak hipotenuzi, dobices povrsinu dva segments, e sada kada bi oduzeo sve moguce pravougle trouglove od odgovarajuceg broja povrsina polukruga, dobio bi zbir svih segments, sto objasnjavaju gornje formule (nije valjda tolko komplikovano)
abver
Jun 20, 2011, 11:48 AM
ideja oko normalne proekcije tacke sa kruznice na poluprecnik, gde ja odnos te, tacke / njene proekcije na radius = precnik / tetive (mat pojam) paralelne sa tom tackom. Ima za posledicu mnogo efekata koji ako se pravilno razumu mogu da daju dosta rezultata. Medjutim najvazniji predstavja niz kojim se izracunava funkcija sinus, gde svaki deo niza similuje (glumi) tu proekciju. Zatim da projektovana tacka ustvari konvertuje pravougli (jednakostranicni) trougao ali I u isto vreme ona konvertuje I prostor, I to ne jedan vec beskonacno mnogo razlicitih prostora od kojih se svaki sastoji od povrsina pravouglih (jednakostranicnih) trouglova. Zatim da se povrsina polukruga moze razumeti kao zbir svih kvadrata razlicitih tetiva. Jedna od posledica je I gornji obrazac Medjutim sve ovo funkcijonise samo kod KRUGA I nikakvoj drugoj varijanti I samim tim ova ideja NE MOZE da se iskoristi za neku opstu teoriju. Ovih dana vidjam na ozbiljnim sajtovima, pogresne interpretacije ( zabrinjavajuce )
abver
Jun 20, 2011, 01:01 PM
Napravio sam gresku u gornjem komentaru mislio sam na jednakokraki trougao, ne na jednakostranicni trougao
jcaron2
Jun 20, 2011, 07:12 PM
At least now I know how to say "isosceles triangle" in Serbian. :)