tom

Hello,

I'd like to know if it's possible to use Mathematica to make a particular variable the subject of the equation. I have some horrendous equations to untangle [and I'm not even sure if I've formulated the equations correctly; they are to do with Fluid Dynamics and shocks] and can't fathom how to rearrange them.

Hello,

You know pictures like this:

http://seconddrafts.files.wordpress.com/2007/02/cr...

What are they called, and is there software that can create them?

Thanks.

I'm making a nice box as part of a friend's birthday present, and realised that it's quite easy to make a nice looking box from very cheap materials. Here are some pictures of the product:

http://img507.imageshack.us/img507/6216/box2bz7.jp...

http://img180.imageshack.us/img180/6760/box6do9.jp...

http://img180.imageshack.us/img180/599/box7uk0.jpg

Here they are covered in newspaper but I can cover them in anything, decorative paper, tea stained paper, artificial flowers, and so on.

I was wondering whether I'd be able to make some money from them, selling them to local botiques etc. How would I go about this? Do you think it could work? How much should I sell them to a customer and how much to a retailer?

Thanks for any help and suggestions.

I've noticed a lot of questions on the Yahoo Answers Medicine and Health pages are about passing drugs tests, and it seems like a lot of the askers are American.

What are the drug testing policies like in America? They seem terribly harsh.

In the UK its very unusal to be asked to take a drugs test, the only check if they have reason to suspect that you've been taking drugs. I've only known one person to have taken a drugs test and that was because his mother was worried about him smoking marijuana while being quite young, and so she requested it. I believe that technically he had to consent to the test, although of course refusal could be taken as acceptance of guilt.

Integrate[Cos[x]*Sin[x]^3]

I'm frustrated because this is the final integral at the end of a long problem on surface integrals but I can't get it into integrable form.

The main issue is rearranging it into a form that I can integrate. I've been playing around with trigonometric identies but can't seem to get it into shape, help would be appreciated!

Thanks

If this sentence is true then God exists.

The above sentence is purely hypothetical and we need not believe beforehand that the sentence is true or that God exists. We simply ask IF the sentence is true, THEN does God exist?

If the sentence is true, then what it says is true, namely that God exists. Therefore the answer to the hypothetical question must be yes, if the sentence is true then God does exist. However that's exactly what the sentence states, not that God exists but that God exists if the sentence is true, which is the hypothetical answer just established. Therefore the sentence is true after all, and since we have established that God exists if the sentence is true, and it is true, it follows that God exists.

Hurrah!

Clearly this is a paradox as we could replace "God exists" with "God does not exist" but it might be interesting for you to play with and suggest where the error lies.

http://en.wikipedia.org/wiki/Existentialism

I'm very much an existentialist, and in my opinion I think it's the best philosophy to have regarding purpose. An existentialist will always have a purpose and reason for living whether God exists or not, God might provide him with even more of a reason for living, but nothing can detract from his original existential purpose.

I find it quite nice to think the people can make their own purposes without relying on anything else.

Hey,

I'm looking for a third person action game in a similar vein to the Prince of Persia series and Ninja Gaiden. Those kind of platforming and fighting games I really enjoy, but on the PC most games fall into the genre of RTS, FPS or RPG. If anyone could give me some suitable ideas, I'd appreciate it. I don't really have enough time to 'get into' an RPG, and I still haven't completed Oblivion!

Thanks.

I've been struggling with this problem for a while and can't find a solution.

Let M2n be the set {1, 2, 3, ..., 2n}

n+1 integers from the set are chosen.

Show that at least two of the numbers satisfy a|b; meaning a is a divisor of b.

Suppose I have a sequence An. If I define m=n+1 and then define another sequence Bn=Am - An and can prove Bn is null [convergent to zero], and inductively prove that a sequence Bn defined from A using m=n+L for any L is also null, is that sufficient to prove that An is Cauchy?

I hope it is, and it certainly seems like it is. This would lend itself nicely to a question I'm working on.

I am uncertain whether one is allowed to have repeated elements of a sequence An in a subsequence Bn. If for instance the first few terms of An are:

An = 0, 1, 2, 3, 4, 5, 6, 7...

Is this a possible subsequence:

Bn= 0, 0, 0, 0, 0, 1, 1, 2...

I know elements have to stay ordered, but I am not certain of whether they may be used more than once consecutively. I ask this because as a challenge we were asked to find a sequence from which one could find subseqences that would converge to a) Every rational and b) Every irrational. If repeated elements are allowed then the question could be very simply answered, if not then it is more difficult.

I feel a bit stupid asking this question because it probably has a simple answer and for some reason I cannot work it out.

When you move one magnet close to another magnet, they spring towards each other. This is kinetic energy. Where does this kinetic energy come from? Since energy can only be transferred, where is the transfer coming from? There must be an energy loss somewhere, but it doesn't make sense for the magnets to cool down or loose mass.

I can't figure it out.

I was reading a little pyschology today [I stress I know almost nothing about the field, however I am intensely curious about many subjects and while I have studied science and areas of philosophy, never pyschology and my aim is to know the world and myself better, and pyschology fits this bill] and it said that fantasies can indicate things about who you are.

Well I have had two long running fantasies. One is transforming into an extremely powerful beast, unrecogniseable as myself, but powerful enough to destroy buildings, cars etc with my bare hands. Not to hurt anyone, but I think the focus is power, shock and awe.

Another one is wearing masks and being unrecogniseable, the emphasis on being able to walk around freely, attracting the stares of others but since I am masked , it does not matter. I think the emphasis here is on secrecy, disguise and a touch of insiduousness.

What does this suggest about me? Normally I try to be extremely moral and kind in my actions.

Do stupid people exist? Seems pretty non-intelligent to me.

Oh wait, thats right, its really annoying when people point out non-existent flaws in established theories isn't it. Much like the old "if evolution is true why do monkeys still exist?" posed to advocates of evolution.

So if Jesus said that only through him shall you have eternal life, does that mean if you do not believe in him, you will have a finite life?

Even a life forever in hell is still eternal life, so it seems like us atheists/agnostics aren't as bad off as Christians seem to think, because honestly I wouldn't want eternal life. When I die I'd much rather have some proper peace and just not exist at all, lights out, no one home, goodbye forever.

So if I disregard Jesus, will my hope for a finite life be realised? Or am I misinterpreting what he meant.

In a recent question someone asked the question "Who created God". One response, and the generally agreed response, was that he is timeless and has existed for ever and always will. Therefore he doesn't require a creator.

In which case, why does the universe require a creator? One theory of the universe is the "steady state" theory, which states that the universe has simply always existed, although in a different shape, and has merely evolved through a process of natural phenomena into the universe we know today. If you can accept God as being timeless and without creator, than surely you can accept this theory? Which does not require you to believe in a universal conciousness, and does away with the "problem of evil", while explaining the creation of the universe completely adequately?

For more information look here:

http://www.schoolsobservatory.org.uk/study/sci/cos...

Hello, I am trying to write a poem. I will emphasise that I know nothing of the Chinese language or calligraphy. What I have done is to study some Chinese poetry [some Li Bai and Bai Juyi poems] and try and understand their literal translations. It seems more about bringing concepts together to me. I've used a translator [which I am aware are often inaccurate with something as complex as Chinese] and my own personal ideas on which characters look most aesthetic. In all probability this reads like rubbish, but if there is any worth in it could you please suggest improvements. Thanks:

Spring Dusk 春天 黄昏

Day lengthen night 天 加长 夜

Bamboo lengthen toward cloud 竹子 加长 往 云彩

Sun drop toward ground 太阳 下降 往 地面

Petal drop chases sun 瓣 下降 追逐 太阳

Night chases red peony vanish 夜 追逐 红色 牡丹 消失

Two lonely eyes sky upward look 二 孤独 眼睛 天空 看

Stars glimmer bright bright 星 微光 明亮 明亮

Tranquil time thinking of you 平静 时间 认为 您

Hello,

I am a British student in a first year of a mathematics degree, and have met a Chinese student whom I like very much. She is from the Sichuan province, she is also studying mathematics and her English is good but not perfect.

She knows that I like her a lot, at the moment I would say my feelings are stronger than a fleeting attraction but not love. We have been out to restuarants a couple of times, and I often spend afternoons at her house. I have done some research into Chinese culture and asked her certain questions, and I appreciate that in China friendship comes before romantic involvement. I think this is a good thing, and I like her modesty in her dress and the way she speaks. She says that she doesn't really know what to make of me yet, so at the moment I don't know where things are going.

I am patient and understanding so I have no problems with time, but if anyone could offer advice as to "do's and don'ts" as I try to win her heart, I would be very grateful.