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silencer
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Post #332448 - Reply to ( #331611) by Noobsrus |
The last Blood Elf
Member
3:30 pm, Nov 4 2009
Posts: 200
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Quote from Noobsrus ( i j k )
( 2 -3 -1 )
( x y z )
If you find the determinants you end up with
i(-3z - y) - j(2z - x) + k(2y + 3x)
....
There is an infinite number of solution so I'm really confused about the question now... lol
....
You are solving simultaneous equations ( a middle school problem) using matrix O_O and
do it wrong from the beginning O__O
plus, you are trying to find a nonexistent vector O____O
And the solution above is okay, not really pretty though:
f(x) = ax+b
inv f(x) = bx+a
The definition of inverse function: f(inv(f(x)) = x for every value of x
thus a(bx+a)+b = x or (ab-1)x + b +a^2 = 0 for every value of x
---> ab-1=0 and b+a^2=0 ----> a=b=-1
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Althaea
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Post #332547 - Reply to ( #332443) by qwert123 |
Tea Leaf
Member
10:37 pm, Nov 4 2009
Posts: 191
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Quote from qwert123 f(x)=ax+b
to find f^-1(x):
y = ax+b
x = ay+b
y = (x-b)/a
f^-1(x) = (x-b)/a
but : f^-1(x) = bx+a
so
x/a = bx and -b/a = a
b = 1/a and b = -a²
1/a = -a²
a(1/a) = a(-a²)
1 = -a³
a = -1
b = 1/-1 = -1
------
a + b = -2
thanks! i forgot i could do that...but splitting them into two other equations never crossed my mind... ^_^;
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chineserider
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Post #332550 |
Persona non grata
Member
10:43 pm, Nov 4 2009
Posts: 1439
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does anyone know how to do decipher a kind of matrix code?
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story645
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Post #332618 - Reply to ( #332550) by chineserider |
forum bunny
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3:16 am, Nov 5 2009
Posts: 504
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Quote from chineserider does anyone know how to do decipher a kind of matrix code?
be more specific?
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MasamiAkane
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Post #341986 |
Rebel Rebel
Member
8:01 pm, Dec 14 2009
Posts: 1223
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Can someone super smart when it comes to Physics possibly pm me? I'm practically begging anyone. I've got some problems, that I need explained. I'm not looking for specific answers as I have them, but I need the concept explained to me, so that my incapable brain can comprehend -_-
Thanks in advance (to anyone willing to help).
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Toto
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Post #341995 |
Site Admin
8:39 pm, Dec 14 2009
Posts: 2276
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Could you give an example; so, we can see the problems level of difficulty. I can understand basic physics... but the application of calculus in physics I have not done.
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Noobsrus
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Post #342045 |
Wall-o-text
Member
1:03 am, Dec 15 2009
Posts: 367
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Posting here would probably be better Akane, more input the better.
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story645
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Post #342063 - Reply to ( #341995) by Toto |
forum bunny
Member
3:37 am, Dec 15 2009
Posts: 504
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Quote from Toto but the application of calculus in physics I have not done.
I'm tutoring calc based E&M, so I could possibly help with that. Seconding toto and noobsrus that you should just post, 'cause there are lots of science and engineering people floating around this board who may not consider themselves good enough in physics to PM you but may give great explanations to some of your questions.
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BoxBox
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Post #342065 - Reply to ( #342063) by story645 |
Member
3:42 am, Dec 15 2009
Posts: 1668
Warn: Banned
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Quote from story645 Quote from Toto but the application of calculus in physics I have not done. I'm tutoring calc based E&M, so I could possibly help with that. Seconding toto and noobsrus that you should just post, 'cause there are lots of science and engineering people floating around this board who may not consider themselves good enough in physics to PM you but may give great explanations to some of your questions.
Engineering totally pwns any field of science!! 
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Gay book discussion thread
Quote from you_no_see_me_ this is not about cannibalism...please get back on topic
Quote from Toto I think it is exactly the topic. I see nothing wrong. |
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silencer
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Post #342066 - Reply to ( #342065) by BoxBox |
The last Blood Elf
Member
3:50 am, Dec 15 2009
Posts: 200
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Quote from BoxBox Quote from story645 Quote from Toto but the application of calculus in physics I have not done. I'm tutoring calc based E&M, so I could possibly help with that. Seconding toto and noobsrus that you should just post, 'cause there are lots of science and engineering people floating around this board who may not consider themselves good enough in physics to PM you but may give great explanations to some of your questions. Engineering totally pwns any field of science!!
How about Physics & applied Physics ?
I m studying engineering and always feel attached to physical and mathematical science  i chose my major kind of randomly.
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MasamiAkane
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Post #342067 |
Rebel Rebel
Member
3:53 am, Dec 15 2009
Posts: 1223
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Ok, ok. Let me gather my thoughts/info and post them later. There are several reasons I didn't and one is embarrassment >_<, as they seem simple enough. Another is that, this is something I'm turning in as a make-up exam, so I was afraid of disclosing too much info as I fear judiciary reviews (yeah, paranoid much?). I'll go through and make them as generic as I can. It's general college physics so I'm sure you can all understand it except for me . Thanks for the replies c:
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story645
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Post #342070 - Reply to ( #342067) by MasamiAkane |
forum bunny
Member
4:33 am, Dec 15 2009
Posts: 504
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Quote from MasamiAkane one is embarrassment >_<, as they seem simple enough.
We all had to learn this stuff once and most of us were quite puzzled with it, especially the stuff that seems really simple now.
Quote . Another is that, this is something I'm turning in as a make-up exam, so I was afraid of disclosing too much info as I fear judiciary reviews (yeah, paranoid much?)
As long as you're allowed to research stuff and we're not solving the problems for you, it should be fine.
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BoxBox
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Post #342087 - Reply to ( #342067) by MasamiAkane |
Member
5:57 am, Dec 15 2009
Posts: 1668
Warn: Banned
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Quote from MasamiAkane Ok, ok. Let me gather my thoughts/info and post them later. There are several reasons I didn't and one is embarrassment >_<, as they seem simple enough. Another is that, this is something I'm turning in as a make-up exam, so I was afraid of disclosing too much info as I fear judiciary reviews (yeah, paranoid much?). I'll go through and make them as generic as I can. It's general college physics so I'm sure you can all understand it except for me . Thanks for the replies c:
ummm....usually colleges monitors the websites your visit and monitors the chat system as well. So chances are they know what you are doing but just don't care enough to do anything....
Quote from story645 Quote from MasamiAkane one is embarrassment >_<, as they seem simple enough. We all had to learn this stuff once and most of us were quite puzzled with it, especially the stuff that seems really simple now. Quote . Another is that, this is something I'm turning in as a make-up exam, so I was afraid of disclosing too much info as I fear judiciary reviews (yeah, paranoid much?) As long as you're allowed to research stuff and we're not solving the problems for you, it should be fine.
The answer is obviously 42, dughhhh 
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Gay book discussion thread
Quote from you_no_see_me_ this is not about cannibalism...please get back on topic
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MasamiAkane
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Post #342266 |
Rebel Rebel
Member
1:14 am, Dec 16 2009
Posts: 1223
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A person with a mass of M and a volume of V floats on the water. What is the volume of the person above the water?
When an upward force is applied, the volume of the person above the water is increased by X. What is F?
That's all the info I'm given (I'm assuming the density of the water is 1000 kg/m^3). I know that this has something to do with Archimedes' Principle and buoyancy. The question specifically ask the volume of the person above the water, which really confuses me, unless I'm over thinking this.
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Noobsrus
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Post #342268 - Reply to ( #342266) by MasamiAkane |
Wall-o-text
Member
1:21 am, Dec 16 2009
Posts: 367
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Quote from MasamiAkane A person with a mass of M and a volume of V floats on the water. What is the volume of the person above the water?
When an upward force is applied, the volume of the person above the water is increased by X. What is F?
That's all the info I'm given (I'm assuming the density of the water is 1000 kg/m^3). I know that this has something to do with Archimedes' Principle and buoyancy. The question specifically ask the volume of the person above the water, which really confuses me, unless I'm over thinking this.
For something to float in water it has to have a density less than 1000kg/m3.
So if density is mass/volume and you know the mass then you can find out the volume of the person
When you say what is F, I assume you're talking about the upward force.
The boyancy force F is
Quote F = pgV - mg
, where p is the density, g acceleration due to gravity, V is volume, and m is the mass. If you want to know how to derive this equation you can PM me.
Some references
Buoyancy
• The upward force (buoyancy)
acting on a body immersed in a
fluid is equal to the weight of an
equivalent volume of the fluid.
Edit: Sorry I'm abit too lazy to tackle the question, even-though I should be able to do it on the fly since I'm studying buoyancy in fluid statics lol. Just going to give you the theory XD. I too get a feeling I'm over-thinking this, are all the values M V X or F not given? I'm feeling so inadequate right now lol.
Last edited by Noobsrus at 1:36 am, Dec 16
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