To you it's easy but to us, it makes our brains explode
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| some classes... http://www.runestorm.com/forums/viewtopic.php?f=6&t=34237 |
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| Author: | Tyster [ Mon Apr 09, 2007 9:59 am ] |
| Post subject: | some classes... |
So, in my statistics class, , my professor spent an hour talking about station stochastic processes and filled up the board with equations and a function of a sub-function of a sub-function, etc., then tells us that this is never used in reality. Grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr |
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| Author: | Carsomyr [ Mon Apr 09, 2007 10:19 am ] |
| Post subject: | some classes... |
Ugh. I'm never going to take a sadistics class. Calculus is only slightly less infuriating. "Take the triple derivative of the inverse hyperbolic cosine of this function, and then graph the relation to the cotangent of this other function over here. . ." |
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| Author: | DK [ Mon Apr 09, 2007 10:45 am ] |
| Post subject: | some classes... |
"Sir, is the function a polynomial in the nth degree or does it involve imaginary equations...?" Yep... It all works for me... |
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| Author: | Raptorian [ Mon Apr 09, 2007 12:10 pm ] |
| Post subject: | some classes... |
I hate complex algebra... |
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| Author: | Bjossi [ Mon Apr 09, 2007 12:19 pm ] |
| Post subject: | some classes... |
Heh, why all the whining? Algebra and calculus are too damn easy to be pissed off at them. |
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| Author: | SX [ Mon Apr 09, 2007 12:41 pm ] |
| Post subject: | some classes... |
To you it's easy but to us, it makes our brains explode
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| Author: | Bjossi [ Mon Apr 09, 2007 12:42 pm ] |
| Post subject: | some classes... |
That stuff isn't all that hard, seriously. Algebra is just figuring out an unknown number x, y or z. Easy if you use certain methods like splitting the equation into sub-equations. |
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| Author: | James [ Mon Apr 09, 2007 2:36 pm ] |
| Post subject: | some classes... |
Bjossi not every one has your IQ of 200........ math makes my brain explode too 
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| Author: | Carsomyr [ Mon Apr 09, 2007 2:43 pm ] |
| Post subject: | some classes... |
I'm with Bjossi on algebra, it's pretty easy stuff. Most of it is stuff we've learned in some form or another by the age of 10. Calculus is really just more of the same. I just haven't been able to give it the time it needs. Calculus has a lot of memorisation you need to do, but the concepts themselves are fairly simple. Hard part is remembering when to apply what. 
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| Author: | Bjossi [ Mon Apr 09, 2007 3:25 pm ] |
| Post subject: | some classes... |
If the equation has the form ' f(x) / g(x) ' and you are supposed to perform calculus, I believe this is how you do it: (f´(x) * g(x)) - (f(x) * g´(x)) Then there are methods for more situations. Calculus is exactly that; memorizing methods and learn to use each. |
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| Author: | Tyster [ Mon Apr 09, 2007 3:46 pm ] |
| Post subject: | some classes... |
you're close, Bjossi. d/dx(f(x)/g(x)) = (f'(x)g(x))-g'(x)f(x))/(g(x))^2. |
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| Author: | Raptorian [ Mon Apr 09, 2007 4:12 pm ] |
| Post subject: | some classes... |
Wha? *brain implodes* Also take note, I've only recently learnt how to rearrange equations, so I'm allowed to be confused
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| Author: | Bjossi [ Mon Apr 09, 2007 6:36 pm ] |
| Post subject: | some classes... |
Tyster wrote: you're close, Bjossi. d/dx(f(x)/g(x)) = (f'(x)g(x))-g'(x)f(x))/(g(x))^2.
Damn, forgot the g(x)^2 part. I learned this stuff 2 years ago, I'd say I remembered it surprisingly well, hehe. |
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| Author: | DK [ Mon Apr 09, 2007 6:39 pm ] |
| Post subject: | some classes... |
What really gets my brain is the transformation from Differential to Integral equations... |
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| Author: | Bjossi [ Mon Apr 09, 2007 8:52 pm ] |
| Post subject: | some classes... |
I'm not familiar with the English terms; isn't the integral just calculus in "reversed order"? |
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| Author: | DK [ Mon Apr 09, 2007 9:03 pm ] |
| Post subject: | some classes... |
Yep... But it's easier said than done. |
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| Author: | Bjossi [ Mon Apr 09, 2007 9:09 pm ] |
| Post subject: | some classes... |
Yeah, it is a lot easier the other way around though. |
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| Author: | DK [ Mon Apr 09, 2007 10:30 pm ] |
| Post subject: | some classes... |
It's like, you differentiate 7x^8+x^5+2x^2 in 4 degrees, but when you assemble it back to its original equation, there's suddenly a constant (denoted by C) floating by: 7x^8+x^5+2x^2 + C I mean, where the fook does C come from!? |
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| Author: | Tyster [ Mon Apr 09, 2007 11:41 pm ] |
| Post subject: | some classes... |
Here's the quick answer, DK. Consider the equation Ax^2+Bx+C. Differentiating, we get 2Ax+Bx. Where did C go?! The derivative of a constant (C) is 0. So, when you integrate, which is to find an equation that differentiates to give the original equation, you could add any constant and it would still be valid. Also, consider this about the integral of a function f(x), which I will calll F(x): when you evaluate F(b)-F(a), for any range (a through b), that is the change of hight in F(x) [Google/wiki "Fundamental theorem of calculus"]. That change of height in F(x) is the area "under" the curve of f(x). It makes sense that when looking at the difference in height on F(x) between any two points, shifting the function up or down (Adding a constant, C) would have no effect. That is: F(b)-F(a)=F(b+C)-F(a+C). |
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| Author: | DK [ Tue Apr 10, 2007 12:03 am ] |
| Post subject: | some classes... |
I know that, but sometimes there can be multiple constants and you have to separate the main equation into sub-equations to get them. |
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| Author: | Bjossi [ Tue Apr 10, 2007 8:08 am ] |
| Post subject: | some classes... |
I think the C is there because the equation possibly had a simple digit at the end. Like 4 or 12 or 17, etc. This just a precaution thing. 
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| Author: | DK [ Tue Apr 10, 2007 8:29 am ] |
| Post subject: | some classes... |
This is why I hate Particular Solutions... |
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| Author: | Bjossi [ Tue Apr 10, 2007 8:43 am ] |
| Post subject: | some classes... |
You mean the ones where you can find out the C's value? Those were easy, when I remembered them... |
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| Author: | Tyster [ Tue Apr 10, 2007 1:17 pm ] |
| Post subject: | some classes... |
Oh, I think I get what DK's saying about multiple constants. I think he's referring to a situation, where, for example, we have: y''(x)-y(x)=0. This yields the general solution: y(x)= C1*e^x + C2*e^-x. Here, we have two constants because the differnetial equation is in the second degree (because of the y''(x)). Is that what you meant, dk? |
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| Author: | Bjossi [ Tue Apr 10, 2007 4:10 pm ] |
| Post subject: | some classes... |
I didn't go this far in maths I think, there was an introduction to those kind of equations but barely any detail. I can take a course of 603 or 703; I am good at maths but going that far is just crazy unless you plan to be a maths professor or something. |
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| Author: | Sargeant Smash [ Tue Apr 10, 2007 4:27 pm ] |
| Post subject: | some classes... |
WOAH...the highst ill ever go is 2+2=chair^2 Yeah the highest ive ever gotten was math 3 so WOO. |
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| Author: | Bjossi [ Tue Apr 10, 2007 4:47 pm ] |
| Post subject: | some classes... |
Math 303 in my school will detail the cosinus, sinus and tangens. There is no mention of calculus or integral. (those words I mentioned are probably not the English names) |
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| Author: | Tyster [ Tue Apr 10, 2007 10:19 pm ] |
| Post subject: | some classes... |
close. In english, they are sin, cosine (cos), and tangent (tan). What's interesting is that cos is the derivative of sin AND it's simply offset from sin by pi/2. Anyways, I really didn't forsee this thread taking such a direction. Just had to grumble about a waste fo a few lectures (-: |
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| Author: | KylinRage [ Wed Apr 11, 2007 12:28 am ] |
| Post subject: | some classes... |
This is making my head go crazy, too young for this stuff! I'd rather see x=100000000000+900! Seriously, I thought you were typing gibberish for a moment. |
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| Author: | DK [ Wed Apr 11, 2007 6:47 am ] |
| Post subject: | some classes... |
Tyster wrote: Oh, I think I get what DK's saying about multiple constants. I think he's referring to a situation, where, for example, we have: y''(x)-y(x)=0. This yields the general solution: y(x)= C1*e^x + C2*e^-x. Here, we have two constants because the differnetial equation is in the second degree (because of the y''(x)). Is that what you meant, dk?
*faints* The 4 ways to deal with multiple constants... Please, hurt me no more... ;_; |
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