Search found 270 matches

by Eastwinn
Sun Oct 02, 2011 11:49 pm UTC
Forum: Mathematics
Topic: Should we make students memorize the quadratic formula?
Replies: 61
Views: 8876

Re: Should we make students memorize the quadratic formula?

I think it's a bit much to make students memorize it. Just have it written at the beginning of every test for reference. It's a quick Google to find it, if they should ever need it later in life.
by Eastwinn
Sun Aug 14, 2011 1:42 am UTC
Forum: Mathematics
Topic: Minecraft Shorelines are loops?
Replies: 18
Views: 2967

Re: Minecraft Shorelines are loops?

1.

Unless you include the possibility that some seed will generate intersecting lakes in a long chain and continues to do so indefinitely after each new chunk is generated. Does such a seed exist? Doubt it. So I'd go with 1.
by Eastwinn
Sat May 28, 2011 1:49 am UTC
Forum: Mathematics
Topic: ∞ X 0 = -1?
Replies: 19
Views: 2505

Re: ∞ X 0 = -1?

In my math class (8th grade) we're learning about geometry and slopes, it is my understanding that a perfectly vertical line has a slope of 1/0 (∞ or undefined) and a perfectly horizontal line perpendicular to the vertical line has a slope of 0. We also learned that the product of the slopes of 2 p...
by Eastwinn
Sun Apr 03, 2011 10:45 pm UTC
Forum: Mathematics
Topic: What is your favorite proof?
Replies: 41
Views: 5355

Re: What is y'all's favorite proof?

My favorite is definitely using differential equation to prove Euler's Formula. If f(x) = e^(ix), then f'(x) = i*e^(ix) = i*f(x). If f(x) = cos(x) + isin(x), then f'(x) = -sin(x) + icos(x) = i*f(x). So these both are solutions to the differential equation y' - iy = 0, and they both satisfy f(0) = 1...
by Eastwinn
Wed Mar 30, 2011 11:32 pm UTC
Forum: General
Topic: Word filter reverseengineerapalooza
Replies: 172
Views: 17679

Re: Word filter reverseengineerapalooza

I was trying to read a few threads in the math forum but the filters were too much for me. Curse you mods.
by Eastwinn
Sun Mar 27, 2011 8:03 pm UTC
Forum: Mathematics
Topic: How do I evaluate this infinite summation?
Replies: 13
Views: 2318

Re: How do I evaluate this infinite summation?

greengiant wrote:Try the free e-book generatingfunctionology by Herbert S. Wilf if you want to learn how to work with g.f.'s


Wow, thanks for posting this :D
by Eastwinn
Fri Mar 18, 2011 4:24 am UTC
Forum: General
Topic: Has anyone ever called you a genius?
Replies: 85
Views: 11372

Re: Has anyone ever called you a genius?

The issue is that we know enough about a subject to see how much we don't know. To an outsider, we appear to know it all because they know too little about a subject to realize its scope. For example, we all thought our parents were geniuses at math when we were little because we didn't know there w...
by Eastwinn
Mon Mar 14, 2011 10:56 pm UTC
Forum: Language/Linguistics
Topic: Using 'there' twice in a row
Replies: 19
Views: 3856

Re: Using 'there' twice in a row

"Weren't" is correct because it refers to "kids". "There" is technically the subject, but it's actually a dummy pronoun so it doesn't really mean anything without the rest of the sentence. And "there" is unmarked for either singularity or plurality. Oh that m...
by Eastwinn
Mon Mar 14, 2011 9:44 pm UTC
Forum: Language/Linguistics
Topic: Using 'there' twice in a row
Replies: 19
Views: 3856

Re: Using 'there' twice in a row

Might be a noob question.. but wouldn't wasn't be correct rather than weren't? I can't seem to decide. What is the subject of that clause anyhoo? there? Is there plural, singular, or what?

Not to derail the thread, of course.
by Eastwinn
Mon Feb 21, 2011 6:45 pm UTC
Forum: Mathematics
Topic: Infinity and Paradoxes
Replies: 5
Views: 1341

Re: Infinity and Paradoxes

What you've shown is manipulation of symbols without meaning. A divergent sum doesn't actually represent a value, so how can you subtract them? Just another example of how intuition seems to fail us when dealing with infinities.
by Eastwinn
Tue Jan 25, 2011 2:13 am UTC
Forum: General
Topic: Hype your ripe snipes 'n' gripes
Replies: 28619
Views: 3490720

Re: Rant Thread (because we need more ranting)

^ I can relate. It makes me cringe whenever someone says a variant of "I'd kill myself if ________" ... I'm not necessarily offended, and it only really hits me emotionally if I'm in a bad mood anyway, but it think it contributes to our culture's tendency to take suicide lightly. That and ...
by Eastwinn
Sun Jan 09, 2011 2:07 pm UTC
Forum: Mathematics
Topic: Demonstration Graph (of dependencies on axioms)
Replies: 2
Views: 559

Re: Demonstration Graph (of dependencies on axioms)

CallMeJudas wrote:I found it!!

http://mizar.org/library/tree/


You're not supposed to post a link until you have 5 posts. I'll confirm that the link is legit though. I recommend the text version.
by Eastwinn
Fri Jan 07, 2011 9:17 pm UTC
Forum: General
Topic: resetting my sleep schedule
Replies: 13
Views: 2245

Re: resetting my sleep schedule

mstjarna wrote:This has made life worth living.

5 AM will always come too early.


This is a good suggestion. GNC sells it. Take it at the time of day that you'd like to feel sleepy and your internal clock will conform after a few days. Then you won't need it until you fuck up your schedule again :lol:
by Eastwinn
Fri Jan 07, 2011 12:40 am UTC
Forum: Mathematics
Topic: Example of a student learning*
Replies: 15
Views: 2352

Re: Example of a student learning*

I never understood why \(\frac{(\sqrt{3}+1)^2}{2}\) was preferable to \(\frac{\sqrt{3}+1}{\sqrt{3}-1}\). Sure, it can sometimes be easier to deal with (like when performing a mental estimation) but often it is just wasted effort to convert from one to the other. I prefer rationalized denominators b...
by Eastwinn
Thu Jan 06, 2011 10:36 pm UTC
Forum: Mathematics
Topic: Example of a student learning*
Replies: 15
Views: 2352

Re: Example of a student learning*

You didn't require them to rationalize the denominator?
by Eastwinn
Wed Jan 05, 2011 10:23 pm UTC
Forum: Mathematics
Topic: "Filling in" a function
Replies: 8
Views: 1657

Re: "Filling in" a function

There are plenty of functions that satisfy f(x+1) = f(x) + x + 1. You'll have to give another property that will define a unique function. For example, Gamma is the unique function that satisfies f(x+1)=xf(x), f(1)=1, and log convexity. Those properties together only belong to the Gamma function. Yo...
by Eastwinn
Mon Jan 03, 2011 2:11 am UTC
Forum: General
Topic: Hype your ripe snipes 'n' gripes
Replies: 28619
Views: 3490720

Re: Rant Thread (because we need more ranting)

I hate how our culture trivializes ADHD. It's fucking serious business, and it does exist.
by Eastwinn
Sat Jan 01, 2011 10:58 pm UTC
Forum: Mathematics
Topic: A little conundrum with infinity
Replies: 9
Views: 1642

Re: A little conundrum with infinity

Hmm..

Well, the blue part takes up a whopping 0% of the plane, so I'd say the chances are 0 for blue.
by Eastwinn
Wed Dec 29, 2010 10:18 pm UTC
Forum: Mathematics
Topic: The Interesting Parts of Maths
Replies: 13
Views: 2825

Re: The Interesting Parts of Maths

Fractal geometry, maybe?
by Eastwinn
Wed Dec 29, 2010 4:13 pm UTC
Forum: Mathematics
Topic: Proof for intergral dx/x=lnx?
Replies: 12
Views: 7716

Re: Proof for intergral dx/x=lnx?

Ah, continuity, I knew I was forgetting something. I'll try my hand at proving that that's enough :D
by Eastwinn
Wed Dec 29, 2010 6:28 am UTC
Forum: Mathematics
Topic: Proof for intergral dx/x=lnx?
Replies: 12
Views: 7716

Re: Proof for intergral dx/x=lnx?

I have a question. Does anyone have a proof that f(xy) = f(x) + f(y), f(e) = 1, defines a unique function for positive, real x and y, provided that it truly does? In that case, I would think that to be the most efficient definition of ln.
by Eastwinn
Fri Dec 24, 2010 6:37 pm UTC
Forum: Mathematics
Topic: Could someone explain this to me? (continuous function)
Replies: 26
Views: 2974

Re: Could someone explain this to me? (continuous function)

There is no choice of c which makes the function smooth anyways. That's true, c=0 only earns it once-differentiability at x=0. Right? (I'm fairly new to the more rigorous aspects of calculus, I'm just taking it this year at school. Edit: In fact, I shouldn't have even been trying to answer this que...
by Eastwinn
Thu Dec 23, 2010 4:24 pm UTC
Forum: Mathematics
Topic: Could someone explain this to me? (continuous function)
Replies: 26
Views: 2974

Re: Could someone explain this to me? (continuous function)

Nope, still missed the reference. :) And that line was addressed to you. The rest was more ... vaguely frustratingly aimed. Oops, looks like I caused a mess. Yesterday I read "continuous" as "smooth" and wrote "smooth" as "continuous". Suffice to say it was n...
by Eastwinn
Wed Dec 22, 2010 4:46 pm UTC
Forum: Mathematics
Topic: Could someone explain this to me? (continuous function)
Replies: 26
Views: 2974

Re: Could someone explain this to me? (continuous function)

EDIT: See above post. OP, ignore this discussion.
by Eastwinn
Wed Dec 22, 2010 3:30 pm UTC
Forum: Mathematics
Topic: Could someone explain this to me? (continuous function)
Replies: 26
Views: 2974

Re: Could someone explain this to me? (continuous function)

EDIT: Nevermind, I was waaay confused about the question. :oops: Too early in the morning to be reading math. :P
by Eastwinn
Tue Dec 21, 2010 6:46 pm UTC
Forum: Mathematics
Topic: Strange Calculus Question
Replies: 8
Views: 1177

Re: Strange Calculus Question

Interesting, thanks for the responses. :D
by Eastwinn
Tue Dec 21, 2010 4:29 am UTC
Forum: Music
Topic: Places to learn Music Theory
Replies: 22
Views: 4324

Re: Places to learn Music Theory

In Jazz, mode means something way different, but unfortunately the names are all the same so it's hard to tell who's talking about what :P . It leads to heaps of confusion in the guitar world alone.
by Eastwinn
Mon Dec 20, 2010 12:40 am UTC
Forum: Mathematics
Topic: Strange Calculus Question
Replies: 8
Views: 1177

Re: Strange Calculus Question

This is question I've been curious about for ages. If h can be defined in terms of f and g, sweet.
by Eastwinn
Sun Dec 19, 2010 9:07 pm UTC
Forum: Mathematics
Topic: Strange Calculus Question
Replies: 8
Views: 1177

Strange Calculus Question

I have no idea how to search this. Let's say I have two continuous functions on (0, c), f(t, x) and g(t, x), for which the following have no known closed forms: \int_{0}^{c}f(t,x)dt \int_{0}^{c}g(t,x)dt If I write this: \int_{0}^{c}f(t,x)dt\int_{0}^{c}g(t,x)dt = \int_...
by Eastwinn
Sun Dec 19, 2010 3:00 am UTC
Forum: Mathematics
Topic: ln(x) or log(x)?
Replies: 63
Views: 9136

Re: ln(x) or log(x)?

I alternate between them. :D
by Eastwinn
Wed Dec 15, 2010 1:49 pm UTC
Forum: Mathematics
Topic: Useless Math
Replies: 60
Views: 9947

Re: Useless Math

Exactly. This is a philosophical question that happens to be about math. The search for an example is a part of a larger attack on the ontology of mathematical objects (numbers, sets, shapes etc.). What I'm trying to say is that they they (inclusive of irrational and complex numbers just the same a...
by Eastwinn
Mon Dec 13, 2010 11:08 pm UTC
Forum: Music
Topic: Places to learn Music Theory
Replies: 22
Views: 4324

Re: Places to learn Music Theory

Yeah, Wikipedia isn't a very good source in this case.

Oh, and don't get caught up with modes. Just worry about tonality.
by Eastwinn
Sun Dec 12, 2010 6:57 pm UTC
Forum: Music
Topic: Places to learn Music Theory
Replies: 22
Views: 4324

Re: Places to learn Music Theory

I always recommend the site musictheory.net .
by Eastwinn
Sun Dec 12, 2010 2:23 am UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 485719

Re: Favorite math jokes

Hopefully not a repost: The Flood is over and the ark has landed. Noah lets all the animals out and says, "Go forth and multiply." A few months later, Noah decides to take a stroll and see how the animals are doing. Everywhere he looks he finds baby animals. Everyone is doing fine except f...
by Eastwinn
Fri Dec 10, 2010 10:24 pm UTC
Forum: Language/Linguistics
Topic: Do you use the term "Ginger"?
Replies: 65
Views: 20285

Re: Do you use the term "Ginger"?

Where I'm from, "ginger" is used to describe someone with red/orange hair, pale skin, and light brown/orange freckles.
by Eastwinn
Thu Dec 09, 2010 12:51 am UTC
Forum: General
Topic: Hifaleetin' thoughts
Replies: 90200
Views: 9116876

Re: Momentary/Meandering/Meditations (Random like the plague

Do Hindus generally find "holy cow!" to be offensive?
by Eastwinn
Mon Dec 06, 2010 1:44 am UTC
Forum: Mathematics
Topic: Useless Math
Replies: 60
Views: 9947

Re: Useless Math

Fractals were once believed to have no practical application, I think.
by Eastwinn
Sun Dec 05, 2010 11:04 pm UTC
Forum: Mathematics
Topic: Forming a proof about a triangle
Replies: 10
Views: 1650

Re: Forming a proof about a triangle

Um... no. You've just proved the converse . The converse does not imply the original problem. What would be an equivalent thing to show is the contrapositive, which in this case would be to show that if a right triangle is not isosceles, then its area is not z^2/4. Right, right. But I thought it wa...
by Eastwinn
Sun Dec 05, 2010 6:11 pm UTC
Forum: Mathematics
Topic: Forming a proof about a triangle
Replies: 10
Views: 1650

Re: Forming a proof about a triangle

You reached this result in a really roundabout way. Start with the formula for area: A=(xy)/2 Using the assumption that x=y: A=(x^2)/2 But, using that same assumption on the Pythagorean Theorem: z^2 = x^2 + y^2 z^2 = 2x^2 (z^2)/2 = x^2 So by substitution: A = ((z^2)/2)/2 Simplify and you have your r...
by Eastwinn
Sat Dec 04, 2010 11:10 pm UTC
Forum: Mathematics
Topic: Would this be a proof?
Replies: 14
Views: 1731

Re: Would this be a proof?

Next step: prove that there is an infinite amount of coprime Pythagorean triples...

:D

Edit: By the way, I agree with the post below me. The way you wrote it was neither concise nor particularly clear. But the idea was definitely there.

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