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130 Comments
- desistere, on 10/11/2007, -2/+98The people of the Digg community might be better served by refreshing their high school English skills.
- woojoo, on 10/11/2007, -5/+34f(x) = x^2
whereas x represents the number of diggs, and f(x) represents represents the number of 403s - shortkid422, on 10/11/2007, -2/+30Likewise, I could say the same about history since I am a Computer Science major. It really depends on what you want to do with your life.
- venom8599, on 10/11/2007, -3/+28Factoring polynomials? No, not again... *curls up in the corner sobbing*
- arcooke, on 10/11/2007, -0/+25I've been out of school for 8 years now.. this isn't a refresher, it's a foreign language.
- atbnet, on 10/11/2007, -2/+20x = 1
- Firehed, on 10/11/2007, -4/+19The average IQ in the world, by definition, is 100. What that 100 represents is what's quickly dropping.
- IneffablePolk, on 10/11/2007, -2/+15Seems like there are a lot of people saying "you should learn math because it will help you in life," and a lot of people saying "I shouldn't learn math because it won't help me in life."
Am I the only one who thinks that any knowledge or education is good regardless of whether you have a specific use or need for it? - msgyrd, on 10/11/2007, -0/+13Good thing you don't live on a hill.
- VillaStraylight, on 10/11/2007, -11/+2342.
- masnevets, on 10/11/2007, -1/+11Knowing math isn't directly helpful most of the time, but from my experience, the more math one studies, the better they become at solving problems which are not necessarily related to math. The reason companies like math majors usually isn't because of what theorems they know, but because they know that successful students of math know how to think.
- dantidote, on 10/11/2007, -0/+9Today is my last day of high school. WOOOO. Math exam second hour. Wish me luck.
- gummih, on 10/11/2007, -0/+8400+3 = Forbidden!
- masnevets, on 10/11/2007, -0/+7@msgyrd
I'm really not sure how you reduced that equation to anything simpler. - SirNoobius, on 10/11/2007, -2/+9y''+xy'+y=0
solve - kirakun, on 10/11/2007, -0/+7@krazikamikaze,
You're good! I didn't see that. Instead, I solved it by power series expansion and equating coefficients. - krazikamikaze, on 10/11/2007, -0/+7@sirnoobius
y(x) = exp(-x^2/2)
Obviously any linear combo of that. - jivemasta, on 10/11/2007, -6/+13Thus the reason why the average IQ of the world is plummeting. Maybe you don't need it, but the higher math you know, the more trivial everyday math problems become. I'll put it in a more understandable fashion for the demographic that is reading this. Imagine you are a RPG character, when you first start the game, every battle is tough. But as you level up, the earlier areas become trivial one hit battles. The same thing applies to math. You start out where 34 + 37 is tough and you have to write it down on paper. But as you learn algebra you have to do simple addition more and more. Eventually you have done it enough that the basic +-* and / problems can all be done in your head. Then you move on to harder math and you can do simple algebra in your head because you have done it so much. It's not that you will use it, but rather it makes math easier as you learn more.
- twertyto, on 10/11/2007, -1/+7@orbit1979
"Most people will never need those skills" Such an ignorant opinion.
Of course you can live your life in a way where you would never need this stuff. But what if you did know it? How can your life be different? I happen to use this stuff often and I feel I'm living a more productive, fulfilling life as a result of it. You'll never know until you've been there. In fact I use the principals of calculus very often as well and that requires a strong background in algebra. - inactive, on 10/11/2007, -2/+8..aaand I fail
- msgyrd, on 10/11/2007, -1/+7Wow, I see a painful amount of intelligent, pro-math comments getting dugg down or buried. That is just sad, especially for a site full of people who like to think of themselves as superior to the general population.
- zKman, on 10/11/2007, -3/+9Google cache:
http://72.14.209.104/search?q=cache:http://math-blog.com/2007/05/16/refresh-your-high-school-math-skills/ - krazikamikaze, on 10/11/2007, -2/+8@kirakun
That's actually the first ODE with non-constant coefficients I've ever tried. I solved it by recognizing that xy' + y = (xy)', so you get:
y'' + (xy)' = 0
Integrate to:
y' + xy = C
And 1st order is a lot easier to solve than 2nd order.
P.S. I actually only found the homogeneous solution y' + xy = 0. There may be more solutions, I'm not sure. - Anpheus, on 10/11/2007, -2/+7Actually, and interestingly, the mean IQ is increasing when comparing the mean from different generations with the same tests (longitudinal studies.)
And actually, the average person IS smarter than the average person a hundred years ago. After all, school was a luxury a hundred years ago, and school after 12-16 unheard of for the majority of people worldwide.
Education is improving, it's just those people at the top who will always see the rest of the people as being dumb by comparison. Nothing has changed, really. Except, perhaps, the ego of those of us in the top percentiles. - sid0, on 10/11/2007, -1/+6"especially for a site full of people who like to think of themselves as superior to the general population."
With all the moronic comments on Digg, where in the world did you get THAT from? - respekt, on 10/11/2007, -0/+5Temporary mirror: http://visualcsharp.it/refresh.htm
- cwgannon, on 10/11/2007, -1/+6Firehed's both pessimistic and wrong ... yet he's being dugg up?
Anpheus is optimistic and right ... yet he's been dugg down?
Diggtards, for the win. - Tankslap, on 10/11/2007, -3/+7So...one of the following is true:
1) you get paid to wipe your butt
2) you are so rich someone else wipes your butt for you
3) you have a nasty butt
4) you are a liar - msgyrd, on 10/11/2007, -1/+5And just to clarify, I didn't digg you down, I actually dugg your question up so both it and the answers could be seen.
Math is all about learning strategies to approach a problem. What makes people hate math is that learning the strategies takes lots and lots of practice for most people. Hell, math is easily my worst academic skill. I took Calculus3 (vector/multivariable) 3 times before I passed. - kirakun, on 10/11/2007, -1/+5@krazikamikaze,
If you use variation of parameter and assume the second solution to be of the form f(x)e^{-x^2/2} for some function f, then you'll see that f(x) = int e^{x^2/2} dx, where int mean integration. So, the second solution is
e^{-x^2/2} int e^{x^2/2} dx.
Hence, the complete solution to y'' + xy' + y = 0 is
Ae^{-x^2/2} + Be^{-x^2/2} int e^{x^2/2} dx
for arbitrary constants A and B.
Nice working with you. I've learned something at digg!!!! Can you believe it?? haha. - venom8599, on 10/11/2007, -7/+10Algebra is not a waste of time. It comes in handy a lot more than you'd think. Calculus on the other hand, doesn't come in handy much for the majority of people.
- masnevets, on 10/11/2007, -2/+5@msgyrd
You're completely missing the point now. - Mossman85, on 10/11/2007, -1/+4***** you math.
- KidKenosha, on 10/11/2007, -0/+3The way I see it, the real value in maths higher than, say, elementary calculus is mainly in the way it teaches you how to think. I'm in my fourth year of a maths degree at uni, and absolutely none of the stuff that I do day-to-day is really useful to an everyday person. (The last time I thought that was probably during first-year linear algebra.)
On the other hand, my ability to reason through problems is far, far better than it was before I started university. Maths has sharpened my ability to search for patterns and connections in information, which is a skill I find invaluable. I see this as the main point of teaching maths, even in high school - your eighth grade teacher isn't just trying to show you how to find the area of a circle or factorise a quadratic equation, they're teaching you a different way of looking at the world. - kelbear, on 10/11/2007, -0/+2
I've only had up to calc 2 and linear algebra and my grades sucked, B- and below. But I still see cases where learning math helped me. My current job never calls for more than simple calculation but there's more to life than just my job.
I may suck at math, but at least having learned and understood the principles allows me to apply the logic and mathematical relationships to understanding other logical problems, and real-world relationships. Acceleration is a derivative of velocity for example. You can see matrices all the time in file/data structures and organization and sort methods. - Tankslap, on 10/11/2007, -0/+2I'm hearing a lot of people claim that they use advanced math in their daily lives without being given any actual examples. I am pro-math but if you say it's practical and useful to you, tell us why.
- twertyto, on 10/11/2007, -2/+4Algebraically solving an equation means using the rules/laws of algebra to *reduce* an equation down to x = ?. I can't see how that can be done in that equation. The variable in the exponential term seems totally isolated from the variable in the linear term.
Of course in many cases (like this one) you can simply reason (arithmetic) a solution but that technically speaking is not an algebraic solution AND may not reveal all possible solutions.
Another example are differential equations (like the one above) which in most cases cannot be solved algebraically but do have known solutions.
@msgyrd
Sorry I wasn't referring to you digging me down but others who did not look at the problem closely. - KidKenosha, on 10/11/2007, -0/+2Well, Taylor/MacLaurin expansions will get you the "right" answer if you extend them to infinity, but that's kinda cheating in a pre-calculus setting.
- atbnet, on 10/11/2007, -4/+6No need, I have a TI-89. I think that bad boy could do just about everything I learned in high school.
- VViley, on 10/11/2007, -0/+2@boo19
Yet for all of the accelerated learning going on in Asia, there's still a shortfall of qualified people:
http://www.itbusinessedge.com/blogs/sts/?p=127 - luigi1015, on 10/11/2007, -0/+2@hacks
"you guys do calculus in high school?"
We had calculus in high school as an AP (Advanced Placement) class.
I probably would have found those problems relatively easy back in high school when I took the class about 7 years ago. The sad thing is that since I don't use anything more advanced than very basic algebra anymore I couldn't get more than 4 or 5 of those right without help. - nrfx, on 10/11/2007, -0/+2shutup Shutup ShutUp SHUTUP!@!!! Numbers OUT OF MY HEAD!
- joerodriguez, on 10/11/2007, -0/+2good article. the idiots guides to algebra, precalculus, and calculus basically got me through these courses
- joewashere, on 10/11/2007, -1/+3So are we doing this some kids homework for him? Smart move on the part of the kid.
- stevejnotjobs, on 10/11/2007, -2/+4Jobs that make you money that involve maths? How does finance grab you - stockbroking, insurance underwriting, merchant banking, etc? Go to New York or London or any other financial capital, look around a bit, and tell me that maths doesn't make you money -- ask one of the many people in a 911 or F430 waiting at the traffic lights if you're not sure...
- cwgannon, on 10/11/2007, -0/+2Your brain's a muscle, and if you don't use it, it will atrophy. If you don't mind that, enjoy being senile!
- Lnomis, on 10/11/2007, -0/+2If you ask me, it's worth learning this stuff just to get to e^(i*pi) + 1 = 0.
I mean.... wow. - nzodd, on 10/11/2007, -0/+2well if SIN(X) = X + 1, then that means that X = SIN(X) - 1
Actually, if you just do the following in your standard graphing calculator:
"let x = sin(x) - 1"
again and again and again, it will converge to the correct answer (start with say... x = 2... then try x = -2)
Turns out to be something like -1.9345632. Try it out and verify that it satisfies the original equation, pretty cool huh?
Numerical analysis & fixed point iteration FTW
http://en.wikipedia.org/wiki/Fixed_point_iteration - chojin42, on 10/11/2007, -0/+2For non-us readers, can someone explain what you learn in precalculus (highschool ?) and what is left for college?
To give a comparison, here in high school we learn:
- general function studies (continuity, derivation, limit, variation behavior, tangent equation of the function at a point, integration and area/volume computation)
- 2nd degree polynomial equations
- 1st and 2nd degree differential equations
- probability
- conics (I'm not sure it's the same word in English: parabola, hyperbola and ellipse/circle)
- parametric functions
- sinus/cosinus/tangent stuff ;)
- complex numbers and its geometric applications
We have some other geometric stuff, but I think that's the main topics. - jeffguillaume, on 10/11/2007, -1/+3What if I don't wanna?
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