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00:08
Happy vacation, @robjohn. Hope you're safely away from fires.
00:40
The solutions to a quadratic equation $ax^2+bx+c=0$ are$$x=\frac{2c}{-b\pm\sqrt{b^2-4ac}}$$
This is known as the citardauq equation
@TedShifrin well, we are just to the north east of the Creek Fire, but it seems to be blowing south.
Going out to eat. See y'all later.
01:47
Hi, @Akiva DogAteMy. Miss talking with you!
02:23
1:27 - When he got into an argument about category theory.

https://youtu.be/1_oLOdWvyNg
02:55
@AkivaWeinberger That’s the Australian version.
03:09
. o O ( everything happening down under )
:-| yeah it's a real mad house down here the highlight of my week is the purchase of a new fish for the aquarium
03:49
Um I want to comment on asking if analytical method for math.stackexchange.com/questions/1212726 is possible, but I don't have enough karma.
especially the code for implementation of the first answer
04:02
ok comment away not sure if code is going to be received well here but you have enough "karma" to comment here at least
50 karma tho
I'm only at 15
so yeah
I have 179 over at stackoverflow
04:36
why is that stack overflowing though
05:05
so is analytical method possible or not since I cannot contact the original author
what do you mean by analytical method
have you looked at the third answer that was posted? Are you referring to obtaining a numeric solution?
I mean instead of using something like Runge-Kutta for approximation, is there a way to integrate the formula directly by changing the expression?
The first two answers go into some level of detail and provide links to the Wikipedia articles for the integration methods used, I suppose the answer would be yes otherwise they would be wasting their time providing such links, the code is in python, so you will need to be familiar with python for that to be of any value to you I would say
05:53
@robjohn Enjoy your vacations sir.
@Knight thanks
 
5 hours later…
11:01
I got an elementary question. Lets say I have a basis vector v = \partial_1 at a point p, what does it mean (and how) to extend it to a vector field V near p?
11:13
I have an elementary proposal. Who votes in favour of face book's name being changed to "Post hole"?
 
1 hour later…
Bob
Bob
12:35
I am hoping that somebody here can look at my post:
0
Q: Finding a volume using the method of cylindrical shells which is generated by a parabola

BobThis problem is from the 7th edition of the book "Calculus and Analytic Geometry" by George Thomas and Ross Finney. It is problem number 3 of section 5.4 Problem: Find the volume generated when the region bounded by the given curves and lines is revolved about the x-axis. (Note: $x = 0$ is the y-...

13:34
A survey of 100 people was conducted to find the popularity of Tom Cruise, Matt Damon and Robert Downey. 35 people liked watching the movies of Tom Cruise, 33 people liked watching the movies of Matt Damon, and 43 people liked watching the movies of Robert Downey.
11 people said they enjoyed watching the movies of Tom Cruise and Robert Downey but not of Matt Damon, 7 people said that they enjoyed watching movies of Tom Cruise and Matt Damon but not of Robert Downey and 18 people said that they enjoyed watching movies of Matt Damon and Robert Downey. 5% of the respondents enjoyed watching the movies of all the three stars.
How many people enjoyed watching the movies of only one star?
How do we solve these problems? Can somebody having an experience with these types of problems help me?
Is the answer 59?
@Knight venn diagram
14:00
@Mayank no, it’s 34
@LeakyNun I’m a little bad with pictures, can you let me know how to set up the sets (or operations) the given sentences.
For “11 people said they enjoyed watching the movies of Tom and Robert but not of Matt”, is it correct to write $n (A \cap C)= 11$
Where A is the set of people liking Tom and C is the set of people liking Robert.
 
4 hours later…
17:46
Suppose $X$ is Borel and $f:X\rightarrow \mathbb{R}$ is a function such that $\{$ $x\in X$ $:$ $f$ is not continuous at $x$ $\}$ is countable. How would I go on proving that $f$ is Borel measurable?
If $a$ has order $3$ modulo $p$, then $p\nmid a-1$. how to prove this?
Bob
Bob
I could use some help with a calculus problem. Could somebody here look at this post for me:
0
Q: Finding a volume generated by a parabola two ways

BobProblem: Find the volume generated when the region bounded by the given curves and lines is revolved about the x-axis using the disk method. Then find it using the cylindrical shell method and verify that they produce the same result. \begin{align*} y &= x^2 \\ x &= 1 \\ x &= 2 \\ \end{align*} An...

18:48
nevermind, I proved it
@Knight draw a venn diagram with three overlapping circles
user435118
19:25
user435118
Hi everyone. I'm learning bearings and doing one of my first questions on it but not sure if it's correct as the question doesn't have answers. Could someone check it please and check my logic?
user435118
I did interior angles add up to 180 degrees, then 360-146-90 to find one angle of the triangle (124 degrees). Then did (180-124)/2 as it is an isosceles triangle and then added 34 to 28 to get 062.
20:18
@Shaun still studying topoi?
 
1 hour later…
21:31
which algorithm does someone mean when they say "the Groebner basis algorithm"? I'm reading about several algorithms about Groebner basis but I don't know which one gets to be "the" one
reopen ??
-2
Q: $ \zeta_H(s) = \prod_{i = 1}^{\infty} \frac{p_{2i}^s}{p_{2i}^s - 1} = 0 $ a RH analogue?

mickLet $p_i$ be the i th prime. Define $$ \zeta_H(s) = \prod_{i = 1}^{\infty} \frac{p_{2i}^s}{p_{2i}^s - 1} $$ Consider it's analytic continuation. ( feel free to explain that analytic continuation ) Where are the zero's and poles of this function ? Does this function have all it's nontrivial zero's...

@mick can you start by giving the second function another name? The º is almost invisible, use ' instead maybe
@Sophie Done. thanks
21:47
@Sophie googling should bring you right to Groebner basis algorithm, it's finding a finite basis as a module for an ideal of (usually multivariate) polynomials.
It's spelled with an umlaut o though
22:00
@AlgebraicGeometryStudent which is also called Buchberger's algorithm?
(I don't know any algebraic geometry, someone gave this as an answer to a question I made which I thought would be solved with other methods)
@Sophie I think there are 2-3 other well known algorithms some dependent upon which monomial ordering you preselect
0
A: How to efficiently compute the minimal polynomial of a number expressed in radicals?

Yuri NegometyanovEach radical $\sqrt[k+1]a$ forms an array of the variables $(p, p^2,\dots, p^k),$ wherein there is not a problem to exclude them via a simple linear system. In particular, for the expression $x=\sqrt a + \sqrt[3]b$ easily to get $$ \begin{cases} p+q-x = 0\\ p^2=a\\ q^3 = b \end{cases}\Rightarrow ...

I'm having trouble understanding the second implication... I don't see where the determinant came from
@Sophie that's a question about Gauss Jordan elemnation
but they stuck in $\det$ in a weird place
I'd start from problem input and try my own version of GJ elemination on the augmented matrix
@Sophie left him a note in comment section
@AlgebraicGeometryStudent I see
Essentially that's what I'd do. I'm also confused
And I gave them an upvote to prompt them
22:16
0
Q: Asymptotics to $f(2n) = f(2n-1) + \frac{f(2n-2)}{f(n)}$ or $ \ln(f(x)) = \int \frac{1}{f(x/2)} + C $?

mickConsider the sequence $f(i)$ for integer $i>0$ : $f(1) = f(2) = 1 $ $f(3) = 2$ define the remaining by $f(2n) = f(2n-1) + \frac{f(2n-2)}{f(n)}$ $f(2n+1) = f(2n) + \frac{2n-1}{f(n)}$ How fast does this function grow ? What are the best asymptotics ? How to answer such similar questions in general ...

@Sophie i upvoted
You have $a-p^2=a-p(x-q) = 0$ by substituting from the first equation into the second, for example.
Then the determinant must vanish since we have a nontrivial solution $(p,1)$.
I presume the second stuff is more of the same.
@Sophie @AlgebraicGeometryStudent
That's probably what's going on
LOL @probably.
@TedShifrin if you have a $\Bbb{Z}$-module $A$ and an abelian monoid $M$. Is there such thing as a module-monoid
I'm not the right person for that question.
22:24
Or is it just the free $\Bbb{Z}$- module on $M$ quotiented by something
Maybe @Leaky can comment on that.
 
1 hour later…
23:50
@AlgebraicGeometryStudent It's not clear to me what kind of structure are you trying to obtain here, can you elaborate?

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