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Please Obi-sci-kenobi. You're my only hope.
I know this is "homework help question", but I really want to learn the method on how to solve matrices.
This is just one of my problems, but I can't seem to solve it with elementary row operations. An online calculator can solve it, but I can't figure it out. Is the system inconsistent?
The last column is obviously the right side of the equation. Everything to the left are obviously the coefficients.
2 1 3 2 0 1
0 0 1 1 2 1
0 0 0 0 3 0
I managed to simplify it to this:
2 1 1 0 0 0
0 0 1 1 0 1
0 0 0 0 1 0
but I can't figure out what to do from here.
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>>7800858
a solution:
[math] \begin{bmatrix} 0 \\ 0 \\ 0 \\ 1 \\ 0 \end{bmatrix} [/math]
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>>7800858
>2 1 1 0 0 0
>0 0 1 1 0 1
>0 0 0 0 1 0
2 1 1 0 0 -1
0 0 1 1 0 1
0 0 0 0 1 0
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>>7800858
>2 1 1 0 0 0
>0 0 1 1 0 1
>0 0 0 0 1 0
row-1 looks incorrect, should be
2 1 2 1 0 0
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I need a basic answer for a question about R, I'm just starting out
lets say I have a vector of integers called x. Normally, if i try to return certain elements, I can specify x[some range of elements]. What is going on if I try to return x[NA]?
Is this question better suited for /g/?
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>>7800716
Are you trying to find NaNs in a vector?
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It returns NA over and over again, depending on the number of elements in a vector. I know you can use is.na to NA's. I'm just trying to understand the output of x[NA]
Anonymous
Damage to mitochondrial DNA 2016-01-21 21:50:21 Post No.7800621
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Damage to mitochondrial DNA 2016-01-21 21:50:21 Post No.7800621
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Damage to mitochondrial DNA
Anonymous
2016-01-21 21:50:21
Post No. 7800621
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Many diseases related to old age are attributed to damages to mitochondrial DNA that occur during the Oxidative phosphorylation phase of glucose dissimilation. So would a keto diet technically be able to prevent these diseases, since keto means no glucose so no glucose dissimilation to damage the mtDNA.
Right?
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No.
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There are populations, like Eskimos, that are in Ketosis for their entire life spans. Try to find out if they get the diseases you are worried about.
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Come on, go ahead, prove that you're as smart as you all think you are
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I can't figure out how to use a proof by induction on such a sum
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>>7800025
>Capture d’écran
>frogposting
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>>7800025
not sure what Pk(n) is supposed to be...
hey sci /dumbfuck/ here. i need some direction. ive been studying for the SAT on khanacademy and i'm having trouble finding where to start bolstering my mathematical skills. i'm taking the NEW SAT in march so i want to pack in as much study as possible. any help on where to start would be much appreciated.
P.S. i live in the middle of nowhere and my school is one of the worst in the country so thats why i'm using khanacademy
i'm posting my stats so you guys can see it, thanks.
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Geometrist?
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>>7799536
Roundtangle
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>>7799536
topless and bottomless circle
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>>7799536
Fat rectangle
Anonymous
WE WUZ COMPUTA SCIENZ N SHIET 2016-01-20 21:42:01 Post No.7798163
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WE WUZ COMPUTA SCIENZ N SHIET 2016-01-20 21:42:01 Post No.7798163
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WE WUZ COMPUTA SCIENZ N SHIET
Anonymous
2016-01-20 21:42:01
Post No. 7798163
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https://www.youtube.com/watch?v=bp4NkItgf0E
What do you think of a possibility that we're in a computer, or that the universe functions like one as a simulation? Are we really in a matrix?
More info here: https://en.wikipedia.org/wiki/Adinkra_symbols_(physics)
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>>7798163
I got to UMD, had that guy as a professor. He is brilliant.
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>>7798163
I was about to post this, when did he come out with the findings?
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Had a black man for my discussion groups in Real Analysis, he was an OK person, made me regain respect for black people
But the niggers in my class are fucking annoying
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when will the next mind blowing and exciting scientific breakthrough finally happen?
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2020, when some genius figures out quantum gravity
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>>7794495
That already happened. Guy's name is Edward Witten. The breakthrough will be when it is experimentally confirmed.
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>>7794515
isnt all of his work going to be void if string theory turns out to be wrong?
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semi-major axis = 30.06AU
does not obey Titius-Bode Law
therefore rogue planet
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>The formula suggests that, extending outward, each planet would be approximately twice as far from the Sun as the one before. The hypothesis correctly anticipated the orbits of Ceres (in the asteroid belt) and Uranus, but failed as a predictor of Neptune's orbit and has since been discredited further.
Kill yourself, plutofag.
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>>7801522
>failed as a predictor of Neptune's orbit
bcoz rogue, Neptunian
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Is it correct to put into the context of freedom the fact of its non-existence, via association being necessary, that it does not exist as if it were to be defined that it would be bound?
Are we living in the setting sun of the freedom of the universe's plight to define what does not bind it and by extension the means ascertain it once again?
>mfw the Yoda speak is weak with the geeks
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You're like a buddhist who only uses his rational mind.
I guess the real freedom comes with not consciously thinking about these kinds of profound abstract concepts.
Also, this is philosophy. Sage.
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I set up about 12 vacuum manifold in a teaching lab. Regular grease on the stopcocks. Put everything up, then tested the glass stopcocks for leaks. No leaks, bubbler stops when stopcock open and vacuum works well, all is well. I go and check on that shit now months later and little to no change in the bubblers when the stopcocks are open to gas. Any clue? Only thing I can think of is the grease has thickened up in cold weather and clogs things but that sounds wrong. When I plug the bubbler it forces the gas out the open stopcock but when I stop the flow stops. Also jammed a pipe cleaner up the stopcock and that fixes it until I turn the stopcock again. The bubblers have mineral oil, mercury is not an option and the Univ Dept is too cheap to go with the nice setups of the telfon stopcocks with the black handle. Any ideas?
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>>7801447
>Also jammed a pipe cleaner up the stopcock and that fixes it until I turn the stopcock again.
That was going to be my first suggestion.
There's probably a bunch of solvents and shit in the old grease from months of use and this could change the viscosity.
Just begin anew, wash away all the old grease with hexanes and apply fresh.
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>>7801465
I thought that too until I set up a crippled manifold today that I had to plug up a port because somebody stole the stopcock. Cleaned it, greased it and sometimes the stopcocks work and sometimes not. Though reading your reply reminded me that I have some thin brushes that might do better than pipecleaners if the don't bend to shit before they do anything. I also want to trouble shoot things a bit better before I redo 48 stopcocks and end up where I started again.
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>>7801486
Are the stopcocks mated?
Often each port and stopcock are labeled with a number and for best results you need to match the numbers on the port to the number on the stopcock.
Anonymous
Could we theoretically make the common cold go extinct? 2016-01-22 05:25:59 Post No.7801374
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Could we theoretically make the common cold go extinct? 2016-01-22 05:25:59 Post No.7801374
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Could we theoretically make the common cold go extinct?
Anonymous
2016-01-22 05:25:59
Post No. 7801374
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Or if not, could we at least keep it Earthbound?
As in, when we take to the stars we make sure no carriers of the common cold/influenza/HIV/herpes/etc get to come along?
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Oh, it wont be hard to keep it EARTH BOUND if you know what I mean.
pst... We wont live on other planets
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>>7801374
Or, or, we could kill everyone that has the cold right now!
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>>7801411
It's not possible to carry that out, though.
I mean it's only a short isolation program to keep long-term inhabitants of other planets from leaving and carrying an illness with them.
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Hi /sci/
I'm doing work for my organic chem 2 class and it's been about three years since I did the first class in the series. I think I'm understanding the current material being presented but there are a couple of blanks in the middle that I think I'm missing out because lack of background knowledge.
This question is based on carbene addition to alkenes.
Two points I'd appreciate being clarified:
1. In (c), through what mechanism is there a carbene being formed to be able to attack the double bond on the cyclohexene? I'm assuming the third molecule in the equation reacts with tribromomethane to remove an H.
2. In general, the carbene attacks the double bond on the alkene to form a cyclic formation (epoxide?). When I was comparing my answers on chegg, I noticed that in (b) and (e), the carbene's carbon in the product is no longer bonded with I, while in (c), the carbene's carbon in the product *is* still bonded with the original two Br. Why is this?
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Okay, I just figured out the reasoning for question 1. I'd still appreciate input on 2 though.
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>>7801361
>In (c), through what mechanism is there a carbene being formed to be able to attack the double bond on the cyclohexene?
That's the Simmons-Smith reaction, and the mechanism generally gets ignored in undergrad organic classes b/c no one gives a fuck.
>2. In general, the carbene attacks the double bond on the alkene to form a cyclic formation (epoxide?).
Not an epoxide, but a cyclopropane.
In c) the carbene is dibromocarbene (deprotonation of bromoform followed by alpha-elimination of bromide from the anion).
In b,d,e it's a zinc carbenoid. (CH2 bound to Zn)
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>>7801372
argh I fucked up the lettering at the beginning of my reply b,d,e are all simmons smith, c is not
Anonymous
Why Can't We Find Aliens? Climate Change Killed Them 2016-01-22 04:40:25 Post No.7801280
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Why Can't We Find Aliens? Climate Change Killed Them 2016-01-22 04:40:25 Post No.7801280
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Why Can't We Find Aliens? Climate Change Killed Them
Anonymous
2016-01-22 04:40:25
Post No. 7801280
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https://www.youtube.com/watch?v=LL_VGGj3XaQ
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>>7801280
>climate change
Lol
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>>7801280
>Youtube, the text host
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>>7801280
well in earth's history so far there has only been a relatively short window of the right conditions for complex intelligent life to exist so it's not that strange an idea that a lot of reasonably smart alien cunts get killed off by their planet becoming unable to sustain them before they manage to get off their planet.
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What are the best books to start self-studying quantum theory?
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>>7801188
Shankar
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>>7801188
griffiths, shankar, schaums
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