Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#101 Re: Puzzles and Games » Janes cryptic crossword clues » 2010-05-21 02:27:19
Not the answer Im looking for, sorry.
#102 Re: Dark Discussions at Cafe Infinity » Medical news » 2010-05-20 08:08:30
#5. Omega-3
Omega-3 is the name of a family of fatty acids made of chains of carbon atoms of varying length. They cannot be synthesised in the human body, and so must be obtained from our diet. Three members of the family are particularly important to human health. Short-chain alpha-linolenic acid (ALA) is a key molecule found abundantly in green leafy vegetables, walnuts and flax (linseed), math (canola) and soybean oil, broccoli and algae. It is the vital precursor molecule that gets converted by all mammals into two important long-chain relatives in the omega-3 family, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). New Scientist.
#103 Re: Puzzles and Games » Janes cryptic crossword clues » 2010-05-20 07:52:25
Thats correct. 
#104 Re: Puzzles and Games » Janes cryptic crossword clues » 2010-05-20 07:07:31
#15 is wrong; #18 and #20 are correct.
#105 Re: Puzzles and Games » Crossword Help » 2010-05-20 03:33:00
This is my thread:
#106 Dark Discussions at Cafe Infinity » Pakistan blocks access to YouTube and Facebook » 2010-05-20 03:15:20
- JaneFairfax
- Replies: 0
Pakistan has blocked the popular video sharing website YouTube because of its growing sacrilegious content.
Access to the social network Facebook has also been barred as part of a crackdown on websites seen to be hosting un-Islamic content.
#107 Re: Help Me ! » Unbounded function » 2010-05-16 20:28:07
Jane Fairfax, consider the function f(x)=x^3 which is differentiable at every point of R. f'(x) is positive and differentiable at every point and so is f"(x), but f'(x) does not tend to 0 as x tends to infinity.
Sorry, whats your point? The cubic function is not bounded above.
#110 Re: Puzzles and Games » House numbers (my own puzzle) » 2010-05-16 02:37:17
Youve all got the correct answer, as well as some good ideas, but I hope you didnt neglect the last bit of problem, namely that the total of all the house numbers was 100. This is significant to the solution. Without it, youd only be making an unwarranted assumption.
#112 Re: Puzzles and Games » Metamorphosis » 2010-05-14 09:03:51
BOY
BAY
BAT
EAT
PAT
PIT
PIE
#113 Re: Puzzles and Games » Crossword Help » 2010-05-14 08:56:58
Fair Fool turns up with Fur (8)
PASSABLE
#114 Puzzles and Games » House numbers (my own puzzle) » 2010-05-14 03:26:36
- JaneFairfax
- Replies: 20
Heres a puzzle I just created out of the top of my own head. 
I once took part in a survey in which a number of people were asked to give their house numbers. I was one of the first 10 people to be asked. At that point, it was found that if you subtracted 2 from the sum of our house numbers, youd get a number which is divisible by 9, while if you added 9 to the sum of our house numbers, youd get a number which is divisible by 10. Then the rest of the people were asked their house numbers, and at the end of the survey, it was found that the total sum of all the house numbers in the survey was a nice round 100.
My house number is an even number. So, whats my house number? 
#115 Re: Euler Avenue » Tychonoffs theorem » 2010-05-13 07:06:29
Oh, and Andrey Nikolayevich Tychonoff (190693) was a Russian mathematician.
#116 Re: Jokes » Silly Questions Funny Answers! » 2010-05-13 07:04:04
Q: Why did the north pole and the south pole fall in love?
#117 Re: Help Me ! » Unbounded function » 2010-05-11 22:35:03
When I said rigorous, I was thinking of first principles. So
would mean
I suppose we could do that if we stated the problem a bit differently:
I have succeeded in proving from first principles that
for such a function, which may, or may not, be an intermediate result that is required.By the way, last night, while thinking in my sleep (yes, thinking in my sleep 
) about uniform continuity of real-valued functions, I remembered this thread, and then I conjectured if a function whose first and second derivatives are positive cannot be uniformly continuous. I might come up with a proof soon.
#118 Re: Help Me ! » Showing the steps » 2010-05-11 08:19:42
Im sure Identitys equation is correct.
#119 Re: Jokes » Silly Questions Funny Answers! » 2010-05-11 07:52:41
Q: If light travels at 186,000 miles per second in a vacuum, what is the speed of sound in miles per second in a vacuum?
#120 Re: Euler Avenue » Tychonoffs theorem » 2010-05-11 07:48:21
More about Tychonoffs theorem.
Tychonoffs theorem in the infinite case is equivalent to the axiom of choice. The converse to Tychonoffs theorem is also true because if is compact, then each , being a continous projection of , must be compact as well.
#121 Re: Puzzles and Games » Cute little problem I saw on another site » 2010-05-06 07:54:09
In general, for , we have
This is a very neat formula. It also proves that if
then −1 ∊ M[sub]n[/sub]
#122 Euler Avenue » Tychonoffs theorem » 2010-05-06 07:24:21
- JaneFairfax
- Replies: 2
Tychonoffs theorem: http://z8.invisionfree.com/DYK/index.php?showtopic=900
Tychonoffs theorem has applications in modern analysis. It is also used to prove the HeineBorel theorem, namely that all closed and bounded subspaces of are compact.
#123 Re: Dark Discussions at Cafe Infinity » Did you know? » 2010-05-04 11:57:42
#4. Did you know?
As alpha rays are thrown out from their source,
The parent atoms undergo a change;
These helium nuclei need little force
To stop them going past a certain range.
Another radioisotope decays,
And more unseen electronvolts are freed;
But these more penetrating beta rays
Are just electrons with a lot of speed.
Possessing no rest mass and zero charge,
The nuclear gamma photons stream about;
They have a penetrating strength so large
That nothing short of lead will cut them out.
#124 Re: Dark Discussions at Cafe Infinity » Did you know? » 2010-05-04 11:55:18
#3. Did you know?
Allan Ramsay (the younger) (171384) was a Scottish artist, who painted portraits of David Hume and Jean-Jacques Rousseau and was Principal Painter in Ordinary to George III. He was succeeded as Principal Painter in Ordinary to the King by Sir Joshua Reynolds.
#125 Re: Dark Discussions at Cafe Infinity » Did you know? » 2010-05-04 11:53:45
#2. Did you know?
A thiol is an alcohol-like compound in which the oxygen of the hydroxyl group is replaced by sulphur. The thiol group in organic chemistry is thus the group SH.