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#1 Dark Discussions at Cafe Infinity » What to do with a BS in Math » 2012-06-05 18:17:14

Replies: 1

This time next year I'll have a bachelor of science in mathematics. What sorts of jobs might I be able to get, and what sorts of things should I be doing now to help ensure I get said job?

Right now I'm thinking about:

Grad School
Actuarial Work

But I'm curious about other ideas people have. Thanks!

#2 Re: Dark Discussions at Cafe Infinity » Math Dependency Tree » 2012-03-01 07:05:57

MathIsFun: A fantastic idea, though I suspect one that's more difficult and more controversial than mine.

Might I suggest "counting" as the first element?

#3 Dark Discussions at Cafe Infinity » Math Dependency Tree » 2012-02-29 17:44:55

Replies: 3

I'm interested in putting together a math dependency tree, and I'm interested in your help. I'm interested in including branches of mathematics as well as non-math like (theoretical) computer science and physics. My chart so far:


My idea is if someone is interested in quantum computing, or measure theory, or Galois theory, etc., they will be able to look at the chart to see what they need to know first.

Unless anyone has any objections, as this chart expands I will edit the image in this post so that most current chart appears in the first post.

Any and all input is most welcome.

#4 Help Me ! » Software for LaTeXing homework? » 2012-01-28 06:46:36

Replies: 2

I'd like to start typing my homework because I really like the way it looks. I'm used to using LaTeX online, so I feel like that is the way to go.

My question is, what sort of software do I need to create printable documents that allow me to use LaTeX?


#5 Re: Help Me ! » Simplification of a Complicated Radical » 2011-12-16 16:00:12

Initially I thought this hint was unhelpful, but it turns out it was just what I needed. My solution:

This took some manipulation and creative thinking. I'm wondering: is there a method that yields the solution without requiring creativity?

#6 Help Me ! » Simplification of a Complicated Radical » 2011-12-15 13:24:27

Replies: 3

I've been working on this for a few days now and I can't for the life of me make any progress on it. I feel like I'm missing something obvious.

The task at hand is to simplify the following:

The book that this comes from (and my calculator) say that the answer is 2.

Any help (hints, a fully worked out solution, anything...) would be most appreciated.


#7 Help Me ! » Schur Numbers and Ramsey Numbers » 2011-06-22 01:28:43

Replies: 1

I think I'm missing something obvious here, please help.

Towards the end of the Math World article on Schur Numbers ( the inequality S(n) ≤ R(n) - 2 is given, where R(n) is a Ramsey number. Everything I've read on Ramsey numbers says that R has two inputs (, yet in the Schur article, it gives R as a function of one variable.

I can't make any sense of this, please help.

#10 Re: Help Me ! » Where's my mistake? » 2011-05-21 06:49:12

My understanding (which is mediocre at best) is that there's a way to define the zeta function on complex numbers. If zeta is defined on real numbers, (as you did it) I think you're correct in saying it diverges. But when it's define on complex numbers, it converges.

I think this: might be a good place to start.

I would love for someone with some experience to shine some light on this.

#11 Help Me ! » Equivalence of classical and modern definitions of Parabola » 2011-05-21 06:33:00

Replies: 5

Classically, a parabola is the intersection of a cone and a plane parallel to the surface of the cone. Modernly, a parabola is the curve y = Ax² +Bx + C. Can anyone provide a sketch of a proof of the equivalence of these definitions?


#12 This is Cool » Fun math for Eighth Grade » 2011-01-08 11:17:26

Replies: 2

I have the opportunity to be a long term substitute for eighth grade in my local middle school. Part of the curriculum calls for "academic enrichment," a 40 minute period to study something fun (but still educational). I want to spend my time doing math that isn't part of the curriculum and isn't something the students are likely to see in high school.

Yesterday I introduced the students to the Euler Characteristic of a plane by having them draw random graphs and counting the number of vertices, edges and areas for each. After about 30 minutes, half of the class discovered that V-E+F = 1 for all graphs.

Next week I plan on having the students build the Platonic Solids out of drinking straws and yarn. I also hope to work with some number sequences.

Any ideas that I might add to my curriculum? The idea is to get the students actively engaged in doing mathematics, rather than just learning mathematics.

#13 Re: Dark Discussions at Cafe Infinity » Haiku 2 » 2010-12-03 13:47:05

A few months ago I wrote a random Haiku generator in Python. Here are some that it wrote:

A hungry baby
wonderfully but poorly cries
over bright crayons

The cute, little spring
eagerly but sadly walks
through cool, bouncy stars

The happy puppy
poorly, not loudly, kisses
for fractal muffins

The dumb, hungry sky
angrily and sadly thinks
about green lettuce

They're nonsensical, but I think they are funny. I hope you like them.

#14 Euler Avenue » catenary » 2010-07-30 15:07:56

Replies: 4

A catenary is the curve:

If you roll a parabola along the x-axis, the focus of the rolling parabola traces out a catenary. I read this a number of places, but I've yet been able to find, or create, a proof.

Can anyone help? Please?

#15 Re: Help Me ! » Elementary, yet challenging problem... » 2010-07-01 09:56:05

Round 2:

149 = ∫|2x|dx  (-7<x<10)
148 = 37*2^(∑2^-i)  (0≤i<∞)
147= 12110 (base 3)
146 = 100 + 50sin(x) + 4sin(3x)  [x=pi/2]
145 = curve length from 0 to arcsec(46) of ln(cos(x))
144 = Only square Fibonacci Number > 1
143 = CXLIII (roman numerals)
142 = ∑(5+n²)²  [0≤n≤2]
141 = ∑(2-|n-1|²)10^n  [0≤n≤3]
140 = x²(x+3)(4x+1)  [x=2]
139 = 2n+1  [n=integral from 0 to 3 of 23 dx]
138 = f'(6)  [f(x) = (2/3)x³ +4x² +18x + 7]
137 = distance between (12,-5) and (100,100)
136 = zz*   [z = 10+6i]  [z* is the conjugate of z]
135 = 5x^x [x=3]
134 = 10n + ((n+1)(n-1)+1)/n -2cos(π)
133 = ∑11^n  (0≤n≤2)
132 = 10^2 + 2^5
131 = (120x +11x -100 -31)(x+1)/(x^2-1)
130 = 104% of 125
129 = distance between (0,0,0) and (4,7,8)
128 = 2^n  [n = lim (n -> 1) (7x-7)/(x-1)
127 = cuberoot(x-2)=5  [solve for x]
126 = exp(ln(2) + 2ln(3) + ln(7))  [exp(x) = e^x]
125 = (n+1)^(n-1)  [n=4]
124 = Surface area of a rectangular prism with side lengths 2, 4 and 9
123 = ∑(3-n)10^n  [0≤n≤3]
122 = |11+i|²
121 = f(6)   [f(n) = 3*f(n-1)+1, f(0)=1]
120 = Cent et vingt
119 = a^b-(a+b)  [a=2, b=7]
118 = 6!/5 - 62
117 = ∑(3n)²  [2≤n≤3]
116 = (-3+3√(3)i)³-100
115 = max(228x-x²)
114 = a^b-(a*b)  [a=2, b=7]
113 = x² = 15² + (x-1)²  [solve for x]
112 = ∑2^n  [4≤n≤6]
111 = 11² - 10
110 = [see below]
109 = |60+91i|
108 = (a^a)(b^b)  [ab = 6 = a+b+1]
107 = 3 + 54 + 31 + 19
106 = zz*  [z = 5+9i]
105 = Product of first three odd primes
104 = exp(3ln(2))*exp(ln(13))
103 = Sum the roots of x² - 103x + 2652]
102 = curve length from 1 to .25(205 + sqrt(42033)) of x²/2 - ln(2x)/2
101 = ∑ n!*(-1)^(n-1)  [1≤n≤5]
100 = ∑ 2n+1  [0≤n≤9]

If any others need to be LaTexed let me know. It's so tedious I tried to do with out it...

What is your target demographic for this? Are you a teacher? If so, what age group are your students? If you are in fact a teacher, I'd suggest having your students do the rest (numbers 1 through 99). There's a lot more to be gained from creating these formulas than there is to solving them.

I think I'm going to pass on the remaining 99, I've been spending too much of my time on this. If you really want me to them, I will, but as I said... they're super educational (and tons of fun).

#16 Re: Help Me ! » Elementary, yet challenging problem... » 2010-06-30 17:19:34

Any branch of mathematics can be used.. logarithms, trigonometry, complex numbers, lim, rot, div, integrals and derivatives etc... just anything that would give a numerical result.

Counting Down:

200 = 5²(2³-1)(2-1)
199 = 200 + arccos(pi)
198 = √(39204)
197 = 200 - log(1000)
196 = (x-6)²(x-1)²  [x = 2³]
195 = x²-390x+38020 (solve for x)
194 = Area of rectangle with sides 2 and 97
193 = 44th prime
192 =  f'''(π/4)   [f(x) = 3*sin(4x)]
191 = x intercept of y=2x-382
190 = 1+2+3+4+...+19
189 = distance (in meters) traveled at 7 meters/sec for 27 sec
188 = Re[(10+3i)(20+4i)]
187 = area of triangle with base 22 and height 17
186 = number of seconds in 3.1 minutes
185 = distance from (5,5) to (65,180)
184 = 5²√(16) + 80 + |6-10|
183 = x²-136x+3783 [x = 100]
182 = (100*cos(x)+80*sin(x)+2*cos(x+2π))*(√2) [x=π/4]
181 = largest prime factor of 25340
180 = 6∫(x²+2x)dx (evaluate from 2 to 5)
179 = lim (x⇒∞) (179x+3)/x
178 = x-value of the min of f(x) = (x-300)*(x-56)
177 = 175 + ∫sin(x)dx [0<x<pi]
176 = LCM(16,22)
175 = 5² + 5² + 5³
174 = 200 + (-4+6i)(2+3i)
173 = distance from the origin to (52,165)
172 = volume of block with side lengths 2,2,43
171 = n(n+1)/2 [n=18]
170 = 10*(∫(-17/x²)dx) [1<x<∞]
169 = area of circle with radius 13/√π
168 = 10*2^4 + 2^3
167 = 10100111 (base 2!)
166 = 369 mod 203
165 = 11 Choose 3
164 =The shortest possible perimeter of an isosceles triangle with two of its side-lengths 50 and 64
163 = 100*ln(e)+10*log(1,000,000)+ln(e³)
162 = length of the curve (1/3)x³-x+4 from 3 to 165
161 = cuberoot(4173281)
160 = sum first 11 primes
159 = 2^7+31
158 = ∫dx/x  [e<x<e^159]
157 = Im(z) - Re(z)  [z = (8+9i)(4+9i)]
156 = (10-2i)(15+3i)
155 = gcd(775, 465)
154 = Perimeter of a rectangle with side-lengths 50 and 27
153 = (27/3)/((8/2)/68)
152 = ½(18!/16!)
151 = Smallest palindromic number greater than 145
150 = perimeter of a right triangle with leg lengths 25 and 60

More tomorrow. It's time for bed.

(PS, be sure to check all of these before using them. It's very late, so I might have made some mistakes).

#17 Re: Dark Discussions at Cafe Infinity » Artificial Intelligence » 2010-05-01 11:15:22

Geodude wrote:

Can you expand on this please?

Of course. I think "intelligence" is an emergent phenomenon. I don't think a program (or organism) is truly intelligent unless it can learn and I think emotions are a side effect to learning. To the best of my knowledge (which is very, very limited) there are two approaches to AI: the "top down" approach and the "bottom up" approach.

The top down approach is simply programming a computer to be knowledgeable. A program knows something because it is programmed to know something. An example of this I made is here: This is a very simple program that will tell you if a mouse drawn face is smiling or frowning. Try it out by drawing a "smiley face" and then pressing space. How did it know? Simple, when I made it, I told it what a happy face looks like (And what a sad face looks like). This program may give the impression of intelligence, but (as far as I'm concerned) it's not.

The bottom up approach is to program a computer with very simple rules and have the program "learn" over time. Here the program is born stupid but it not stagnant. (I don't have a good example to post, sorry). My belief is that any being (organic or artificial) that can learn will develop emotions. To me, thinking and feeling are the same thing. As far as I'm concerned, the brain is simply a computer and any computer built to be as intelligent as a human brain is probably going to have many of the tendencies. Sufficiently intelligent computers will make mistakes, feel emotions and even behave irrationally.

Two books I recommend: Artificial Life by Steven Levy (non-fiction) and Galatea 2.2 by Richard Powers (fiction). Both of these books explore this topic extensively.

#18 Re: Dark Discussions at Cafe Infinity » Artificial Intelligence » 2010-04-05 04:55:22

MathsIsFun wrote:

Interesting side issue: for a computer to pass the Turing test it would also need to be deceptive. Ask it for the square root of pi and it needs to go "Umm...let me think... about ummm.... 1 point ahhh..."

...or be genuinely bad at math. All of our computers today do computation well, but computers of the future might not work that way. It seems to me, if we want to have truly intelligent and creative computers, we need to make them dumb at some things.

As for why we would want to give computers emotions: I don't think we have a choice. I think emotions are a side effect of true intelligence. I believe that emotions are an unavoidable consequence of intelligence/creativity.

#19 Dark Discussions at Cafe Infinity » Artificial Intelligence » 2010-04-03 03:15:15

Replies: 9

Is artificial intelligence an achievable gain? If not, why? Will we be able to simulate emotions (or will they be actual, not simulated, emotions)?

What advances do we have to make in hardware first? Software?

I'll share my opinions soon; I'm curious to know what everyone else thinks.

#20 Re: Coder's Corner » Python: moving on up? » 2010-03-20 16:43:56

When I use Python, I use IDLE or PyScripter. I don't compile my code, so I guess I'm using a scripted language.

I look forward to someday learning Java, but I simply don't have the time right now. But if I don't have to learn it to use Jython, I can jump right into no problem.

What are typical "needs" of a compiled/scripted language?

#21 Re: Coder's Corner » Python: moving on up? » 2010-03-16 11:45:10

Calccrypto: I don't understand your question. I use IDLE to write my programs (and more recently PyScriptor). Make no mistake, I have no idea what I'm doing, I'm doing this for fun.

Ricky: Wow, that's a whole bunch of techno-lingo, but at least I have a starting place. Am I going to have to learn Java to use Jython? How do I figure out which implementation of Python I'm using? IF I'm using the wrong implementation of Python, how do I use the right one? And how will that change what I'm doing?

#22 Coder's Corner » Python: moving on up? » 2010-03-14 12:25:28

Replies: 6

I've been using Python for a while now (and loving it) but I want to take my programs to the next level. Bear with while I try to explain myself, I've never taken a programming class, so I don't know how to explain myself properly.

I think what I'm asking about is a GUI, but I'm not sure. I want my programs to be usable by someone without that person having to open up the Python IDE (PyScripter or IDLE in my case) and run the code. I want my program to look like something I might download off the internet (like GraphCalc or Gimp, but not so fancy).

So my questions are:
1. Am I making myself clear?
2. Is this what a GUI is?
3. Can I do this using only Freeware (I'm a poor, simple, college student)
4. Can anyone help me get going on this?


#23 Help Me ! » Complex Analysis » 2009-12-29 09:06:50

Replies: 1

I've spent far too much time with this one:

Describe geometrically the sets of points z in the complex plane defined by the following relation:

Re(az+b) > 0 (where a and b are complex)

I have a line with a slope of Re(a)/Im(a) and a y-intercept of Re(b)/Im(a). So what?

Any help would be great.


#24 Help Me ! » Limit of a recursive sequence » 2009-11-12 10:22:40

Replies: 5

I'm stuck here and was hoping someone could give me a push in the right direction.

I'm playing with a sequence:

and I'm looking for

Any advice/answers would be very much appreciated.


#25 Re: Help Me ! » infinite series » 2009-09-24 09:33:15

That's a pretty cool solution, thanks.

Is this a method you just knew because you had seen it before, or did you come to this after being inspired?

I'm just curious, thanks.

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