## #math - Sun 4 Mar 2007 between 20:33 and 21:15

### NY Lost Funds

 Sweetandy Yes, thank you. Oompa LoganCapaldo: So RPN is just about it? LoganCapaldo I dunno, I don't actually have one :)I have an 89(but the on button is flaky, grrr) Oompa heh.. I'm tempted to open it and mess with it but I'd rather if I sell it TRWBW doofy2: which proof did you use? that a hemisphere + a cone = a cylinder? Oompa LoganCapaldo: http://www.ticalc.org/archives/news/articles/3/34/34836.html doofy2 that "proof" talks about drawing triangles on the surface and forming pyramids Oompa or http://www.paxm.org/symbulator/download/rpn.html doofy2 TRWBW, it of course explains the surface area first because it is dependent upon that formula form51 anyone enjoy listening to Morrissey? saimazoon I prefer JoplinShe used to smoke crack TRWBW doofy2: oh, you can do it another way. davock helloi have a question of probability doofy2 i just searched for that, i just know the calculus method TRWBW doofy2: if you stick a cone upside down next to a hemisphere, than any horizontal slice has the same area as the slice of a cylinder doofy2 davock, just ask. davock A Newly married couple decides to continue having children until they have one of each sex.If the events of having a boy and a girl are independent and equiprobable, how many children should this couple expect TRWBW doofy2: cone has volume pi*r^3/3, cylinder has pi*r^3, so hemispher must have (2/3)pi*r^3, and sphere (4/3)pi*r^3 doofy2 TRWBW, of the same size base and height? TRWBW doofy2: they all have a circular base of radius r and height rdoofy2: the cone is upside down doofy2 interesting, i've never seen that Vzoo hi all, what's the equation of the parabole f(x) that touches the Xs in x=1/2 and that respects: u(a)=c and u(b)=c?hi all, what's the equation of the parabole f(x) that touches the Xs in x=1/2 and that respects: f(a)=c and f(b)=c?soz TRWBW doofy2: it's pretty straightforward, at height h from the bottom, the slice of a hemisphere has area pi*(r^2-h^2) and the slice of the cone area pi*h^2 and the slice of the cylinder, well pi*r^2 at any height davock Hint : Sumatory of i=1 --> infinity of (1^(ir^i)) = r / (1-r)^2 TRWBW davock: 3 Vzoo wait i've got it wrong: the parabole f touches tHe Xs in x=(a+b)/2 and has to verify f(a)=f(b)=chow do i find its equation?i don't know the english word for parabole (x^2 like curv)isn't this a very basic question? Tene "parabola" Vzoo close enough, what about the mathematical part of the question ; p fedt so our math teacher actually calls doing volumes where the cross section is square, the floppy disk method prettytoney hi