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On February 02 2012 01:09 DarkPlasmaBall wrote:Show nested quote +On February 02 2012 01:06 achristes wrote:On February 02 2012 01:03 DarkPlasmaBall wrote:On February 02 2012 00:49 Koshi wrote:
2d seems wrong to me. You probably didnt fill in the complete answer or something.
Both going to 3 consecutive meeting would be
(0,6*0,7) ^ 3 = 7,4% I agree with this. P(Nadia going) * P(Tor going) = P(Nadia and Tor going to the same) to the third power, for three meetings. Sorry, my bad. No worries. Are these questions you got wrong on a test? Or questions you got correct but just mis-translated into English? Or something else? Your OP says they were on your last math test, so are you looking to see if you got the answers right? Or are testing us?
I just thought it would be fun to share them, I got all of these questions right, but I forgot to add the last part of 2d and I mistranslated 2a 
Don't forget about the random fun one, it is actually kind of funny, or maybe I just have a weird sense of humour ^^
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On February 02 2012 01:16 achristes wrote:Show nested quote +On February 02 2012 01:09 DarkPlasmaBall wrote:On February 02 2012 01:06 achristes wrote:On February 02 2012 01:03 DarkPlasmaBall wrote:On February 02 2012 00:49 Koshi wrote:
2d seems wrong to me. You probably didnt fill in the complete answer or something.
Both going to 3 consecutive meeting would be
(0,6*0,7) ^ 3 = 7,4% I agree with this. P(Nadia going) * P(Tor going) = P(Nadia and Tor going to the same) to the third power, for three meetings. Sorry, my bad. No worries. Are these questions you got wrong on a test? Or questions you got correct but just mis-translated into English? Or something else? Your OP says they were on your last math test, so are you looking to see if you got the answers right? Or are testing us? I just thought it would be fun to share them, I got all of these questions right, but I forgot to add the last part of 2d and I mistranslated 2a Don't forget about the random fun one, it is actually kind of funny, or maybe I just have a weird sense of humour ^^
I can't read German, but I saw the words Satan and Butter in the lyrics lol.
I read the spoilers too ^^
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Well, I always loved math, because its a mental thingy, but makes perfect sense, not like languages...
So my math, physics, chemistry and informatics tests are A and my latin and german tests are D :/
(English is B,its just better than german :D)
BTW, I am a native german speaker, here is a translation to english(broken english ofc  ):
+ Show Spoiler +The Eggs of Satan A half cup of sugar A quarter of a tea spoon of salt A knife point of turkish hashish A half pound of butter A tea spoon of vanilla sugar A half pound of flour 150 grams of milled nuts A bit more sugar and no eggs Put it into a bowl Add the Butter and the milled nuts and knead the dough Make balls as big as a eye out of the dough and toss them into the sugar, speak the magic words Simsalbimbamba Saladu Saladim (no explanation cuz... you know ) Put them onto a buttered baking plate and bake them at 200°C for 15 minutes and NO EGGS Bake them at 200°C for 15 minutes and NO EGGS
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On February 02 2012 00:57 Koshi wrote:3c is also wrong. 10.000 + 120 * x = 200 * x (x = the amount of attendees) x = 50 + 0,6 x 0,4 x = 50 x = 125 So the answer is 125 students EDIT: I am going home now, I might check the other ones when I get home .
Any feedback on this?
10.000 + 120 * x = cost of the project where x is the number of attendees.
200 * x = Profit of the project where x is the number of attendees.
10.000 + 120 * x = 200 * x (Cost = profit)
x = 125
Making a graph on your calculator and guessing the answer on your test with give you a 0/10 in Belgium .
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On February 02 2012 02:06 Koshi wrote:Show nested quote +On February 02 2012 00:57 Koshi wrote:3c is also wrong. 10.000 + 120 * x = 200 * x (x = the amount of attendees) x = 50 + 0,6 x 0,4 x = 50 x = 125 So the answer is 125 students EDIT: I am going home now, I might check the other ones when I get home . Any feedback on this? 10.000 + 120 * x = cost of the project where x is the number of attendees. 200 * x = Profit of the project where x is the number of attendees. 10.000 + 120 * x = 200 * x (Cost = profit) x = 125 Making a graph on your calculator and guessing the answer on your test with give you a 0/10 in Belgium .
They told us to use digital assets, and this is the answer I got. And FYI I didn't "guess" as you so blatantly put it, I used the function on my calc that shows what the x-value is when y=200. Why the answer is wrong I have no idea.
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On February 01 2012 23:21 ETisME wrote:
maths is fun until you get to a certain level where you starts to have questions that would get illogical (or basically you are required to abandon understanding the theory and learn to just DO maths), first one in my mind was sin, cos and tan.
If you like these kind of maths, stats are more to your taste to be honest
In electrical engineering we learn that trigonometry relates real and imaginary numbers.
![[image loading]](http://agutie.homestead.com/files/e_i_pi_full.jpg)
Years later, I still don't quite understand. I mean, I can apply it, but I don't really GET IT.
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On February 02 2012 04:42 Uranium wrote:Show nested quote +On February 01 2012 23:21 ETisME wrote:
maths is fun until you get to a certain level where you starts to have questions that would get illogical (or basically you are required to abandon understanding the theory and learn to just DO maths), first one in my mind was sin, cos and tan.
If you like these kind of maths, stats are more to your taste to be honest In electrical engineering we learn that trigonometry relates real and imaginary numbers. Years later, I still don't quite understand. I mean, I can apply it, but I don't really GET IT.
Well, if you think of e^x as just "a function f satisfying f' = f and sin x as a solution to f'' = -f, then it's natural to think that there's possibly a way to build e^x out of sinx and cosx.
So you see if it's possible to find numbers a,b,c,d such that e^x = a*sin(cx) + b*cos(cx). Then, plugging in x = 0, we get b = 1, and taking derivatives, we get -bc = a and ac = b, or ac = 1 and -c = a, which then gets us a^2 = -1. So this brings a connection with imaginary numbers, and a = i and c = -i. And we get e^x = isin(-ix)+cos(-ix). You can check that it satisfies f' = f, and if you want this to be rigorous you can prove theorems about what the possible values of f are given that and some more information. If we plug in x = i*y, we get e^iy = cos(y)+isin(y).
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On February 02 2012 05:11 Nehsb wrote:Show nested quote +On February 02 2012 04:42 Uranium wrote:On February 01 2012 23:21 ETisME wrote:
maths is fun until you get to a certain level where you starts to have questions that would get illogical (or basically you are required to abandon understanding the theory and learn to just DO maths), first one in my mind was sin, cos and tan.
If you like these kind of maths, stats are more to your taste to be honest In electrical engineering we learn that trigonometry relates real and imaginary numbers. Years later, I still don't quite understand. I mean, I can apply it, but I don't really GET IT. Well, if you think of e^x as just "a function f satisfying f' = f and sin x as a solution to f'' = -f, then it's natural to think that there's possibly a way to build e^x out of sinx and cosx. So you see if it's possible to find numbers a,b,c,d such that e^x = a*sin(cx) + b*cos(cx). Then, plugging in x = 0, we get b = 1, and taking derivatives, we get -bc = a and ac = b, or ac = 1 and -c = a, which then gets us a^2 = -1. So this brings a connection with imaginary numbers, and a = i and c = -i. And we get e^x = isin(-ix)+cos(-ix). You can check that it satisfies f' = f, and if you want this to be rigorous you can prove theorems about what the possible values of f are given that and some more information. If we plug in x = i*y, we get e^iy = cos(y)+isin(y).
If someone is interested in this he should look for Euler's formula (and how he got there).
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Nice essay, thanks for the link.
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EPT
