420chan now has a web-based IRC client available, right here
Leave these fields empty (spam trap):
Name
You can leave this blank to post anonymously, or you can create a Tripcode by using the float Name#Password
A subject is required when posting a new thread
Subject
Comment
[*]Italic Text[/*]
[**]Bold Text[/**]
[~]Taimapedia Article[/~]
[%]Spoiler Text[/%]
>Highlight/Quote Text
[pre]Preformatted & Monospace text[/pre]
1. Numbered lists become ordered lists
* Bulleted lists become unordered lists
File

Sandwich


Community Updates

420chan now supports HTTPS! If you find any issues, you may report them in this thread
Learn math from scratch by Hugh Shittingdock - Wed, 24 Feb 2016 02:37:19 EST ID:NaTojNkl No.15058 Ignore Report Reply Quick Reply
File: 1456299439874.jpg -(53753B / 52.49KB, 453x604) Thumbnail displayed, click image for full size. 53753
My first semester at the university was fun, every day I smoke wead. But that is not I was supposed do, so now I have to learn all the stuff, from limits to integrals and from matrices to geometry. Can you suggest some cool books for me, guys?
And excuse my English.
>>
Lillian Clayfoot - Tue, 01 Mar 2016 12:21:48 EST ID:jM5wsKbL No.15062 Ignore Report Quick Reply
1456852908437.jpg -(777835B / 759.60KB, 1024x768) Thumbnail displayed, click image for full size.
I had a calculus for dummies that was great.

protip: leave a spare hour after your math classes to work on your assignments while the knowledge is fresh, then you dont have to worry about as much homework.

also, be keen and go ask your prof questions. its their job and your respnsibility to ask when your confused


Unsolved Zodiac ciphers by Angus Honeyfoot - Tue, 23 Feb 2016 23:40:50 EST ID:edLsgdZo No.15057 Ignore Report Reply Quick Reply
File: 1456288850535.png -(278484B / 271.96KB, 475x642) Thumbnail displayed, click image for full size. 278484
Has anyone taken a crack at this?
>>
Esther Desslefure - Mon, 29 Feb 2016 12:42:19 EST ID:J4OUpAxW No.15061 Ignore Report Quick Reply
How do wewe even know thait's not meaningless gibberish, like thishttps://en.m.wikipedia.org/wiki/Voynich_manuscript


Big O by Esther Nazzlebig - Sun, 28 Feb 2016 18:08:48 EST ID:uLlpzKkX No.15059 Ignore Report Reply Quick Reply
File: 1456700928519.png -(675671B / 659.83KB, 1106x1012) Thumbnail displayed, click image for full size. 675671
This may be better suited for /prog/ but I'll try here.

15n + 62 = O(n)
15n + 62 <= c * f(n)

I need to find a C less than 40 and solve for k.
The answer is C = 16, K = 62, where 15n + 62 <= 16n, simplified to give you 62 <= n. This is what my textbook has as the answer.

Can anyone explain this to me? I don't understand, why is K = 62? I understand this is marking the point where one side of the equation passes the other side, but I don't know how 62 plays into that at all.
>>
Esther Nazzlebig - Sun, 28 Feb 2016 18:14:55 EST ID:uLlpzKkX No.15060 Ignore Report Quick Reply
Hey nevermind, it's 62 because 15(62) + 62 <= 16(62). That was easy.


Diff Equations: Exact Equations by Sophie Goodstone - Tue, 23 Feb 2016 00:53:02 EST ID:qCDKBx4v No.15052 Ignore Report Reply Quick Reply
File: 1456206782611.jpg -(123714B / 120.81KB, 945x945) Thumbnail displayed, click image for full size. 123714
Please help.
Determine the constant c so that the differential equation is exact.
(x+cy+ 2)dx + (y-x)dy = 0
>>
Sophie Goodstone - Tue, 23 Feb 2016 10:49:58 EST ID:qCDKBx4v No.15053 Ignore Report Quick Reply
If Exact Equations are of the form M(x,y) + N(x,y)*(dy/dx) = 0
Then my guess would be to divide the whole thing by dx first. so we get:
(x+cy+2) + (y-x)(dy/dx) = 0

Okay.. so.
M=x+cy+2; N=y-x
; So.. first check if the partial derivative of M with respect to y is equal to N partial respect to x..
My = 0 wtf
Nx = -1 okay wtf!

Help!
>>
Sophie Goodstone - Tue, 23 Feb 2016 11:52:28 EST ID:qCDKBx4v No.15054 Ignore Report Quick Reply
>>15053
No. Wait.
c= -1 Correct?
>>
Hedda Dirrydog - Tue, 23 Feb 2016 13:50:22 EST ID:A2j/BW/W No.15055 Ignore Report Quick Reply
>>15054
That's correct, but your work >>15053 is all screwed up. You're supposed to be integrating, not taking partial derivatives.
>>
Hedda Dirrydog - Tue, 23 Feb 2016 13:58:11 EST ID:A2j/BW/W No.15056 Ignore Report Quick Reply
>>15055
You're supposed to find the potential function, which turns out to be F(x, y) = 1/2x^2 + 1/2y^2 + 2x - xy + z where z is the constant of integration.


for a er secret project by Polly Fanstock - Wed, 30 Dec 2015 04:20:23 EST ID:8sbm1RBU No.15010 Ignore Report Reply Quick Reply
File: 1451467223718.png -(15640B / 15.27KB, 819x460) Thumbnail displayed, click image for full size. 15640
got an answer??

it goes line by line not a whole sentence x
>>
Nicholas Pockdock - Thu, 31 Dec 2015 07:58:38 EST ID:WhsPRodl No.15011 Ignore Report Quick Reply
Penny = million
Hundred penny = 100 million = pound
Hundred million pound = Hundred million pound
>>
Angus Sorryforth - Thu, 31 Dec 2015 08:05:36 EST ID:8sbm1RBU No.15012 Ignore Report Quick Reply
>>15011

isnt it to do with money so
penny=million
hundred penny = £100million
£100million x £100million = hundred penny x hundred penny?
= £10000
>>
Shit Snodbury - Sun, 21 Feb 2016 14:11:34 EST ID:WhsPRodl No.15051 Ignore Report Quick Reply
>>15012
No because you see that a
penny = million
so
100 penny v 100 million = 1 pound
therefor
1 million = 0.01 pound
0.01 pound * 100 million/penny = 1 pound

f(x)= 0.01x

It has nothing to do with money, but with the prefixes and the specific numeral system (base 10 decimal)
I could might as well have been apples and pies


Where to start? by Betsy Sunderforth - Mon, 14 Dec 2015 02:29:48 EST ID:hlhZo5V6 No.15000 Ignore Report Reply Quick Reply
File: 1450078188284.jpg -(226445B / 221.14KB, 1000x744) Thumbnail displayed, click image for full size. 226445
Hey /math/,
I need some help. I have always been shit at math. I never studied throughout high school and got mostly C's or D's in math while maintaining straight A's in the rest of my classes. It was mostly due to me not completing homework, but I also failed to grasp a lot of concepts.

So now that I'm in college I'm fucking up hard in math. I have to take a class I already took in high school because I did so bad on the placement exams. And I just failed it. My goal is to get serious and focus on math more, however I have no idea where to start.

I'm in "Intro to College Algebra" which basically covers pre- algebra through algebra 2 with a little geometry sprinkled in. With that in mind, where the hell do I start? What material is out there that I should cover? Could you guys be so kind as to show me in the right direction as to where to study, whether it be Khan Academy or a particular set of text books. I feel as if I need to start towards the bottom of math knowledge because I honestly don't even remember the rules for working with fractions all the way back in elementary school.

Thanks guys.
4 posts omitted. Click Reply to view.
>>
Whitey Worthingson - Wed, 23 Dec 2015 00:42:28 EST ID:IW8qyMi3 No.15008 Ignore Report Quick Reply
>>15000
i stoped trying to get math at second year of HS
i always sucked at it, and thought it was pretty useless (aside from basic stuff)
i really dont know nothing, im at the level of a 8 year old, hell, im pretty sure there must be tons of 8 year olds who know more math than me
when i say i stopped trying, i mean it, i never ever paid attention.
wat do
will this khan academy help me? or should i just kill myself?
>>
Sidney Sommermon - Sat, 26 Dec 2015 17:43:40 EST ID:nHMNF5Fv No.15009 Ignore Report Quick Reply
>>15000
i reccommend "wolfram alpha" for things too. its a great way to figure stuff out. just type the equation in and it shows you how to solve it.
>>
Shitting Fushbury - Wed, 03 Feb 2016 10:45:39 EST ID:OD6ADxvT No.15037 Ignore Report Quick Reply
Im somewhat impressed that you really do wish to turn your issues in mathematics around. Usually once someone has put Math off for so long they just dont have the will to get back to it.

Khan Academy is the best free resource and you should be on it every day for at least 20 minutes for extra practice. Do all the homework to the best of your ability and turn it in conpleted. On exams answer everything to the best of your ability and try and leave nothing blank. Partial points are better than nothing but this is more crucial in higher level classes.

Start at geometry and equation solving. If your unsure about algebra rules find examples before you practice something illegal for a week straight. Ive seen plenty of kids try and simplify the sum of two squares inside a square root :/

This was my study progressio before college after I spent 2 years washing dishes after high school.
Algebra1/geometry >> algebra2 >> pre calc 1/2 >> calculus
Calculus.
Differential >> integral >> vector >> series >> multivariable

Linear Algebra and Diff.Eq can be taken anytime after integral calculus.
>>
Henry Fommlefield - Mon, 15 Feb 2016 19:36:38 EST ID:RHLOntyV No.15047 Ignore Report Quick Reply
>>15005
not to be that guy, but I think you're thinking of Velleman's how to prove it, Polya wrote "How to Solve It," which is a great book in its own right.
>>
Doris Nundlechodging - Wed, 17 Feb 2016 03:50:13 EST ID:aLV1scJv No.15048 Ignore Report Quick Reply
>>15009
symbolab is free though

wolfram is just mathematica stripped down so you could just pirate that


Prolem Sets for Group Theory Class by Hamilton Crubbleshit - Sat, 07 Nov 2015 07:06:32 EST ID:q3ZVtHN5 No.14966 Ignore Report Reply Quick Reply
File: 1446897992036.png -(8060B / 7.87KB, 220x229) Thumbnail displayed, click image for full size. 8060
So I'm taking a Group Theory class and we are using the book Undergraduate Algebra by Serge Lang.

It's a good book except that there's not solution manual so it is pretty useless to practice problems.

Can any of you please share any problem sets with solution, you had if you also took this class?

Or maybe a book on group theory that has both practice problems and solutions?

Pic unrelated.
1 posts omitted. Click Reply to view.
>>
Edward Dottingkot - Sun, 15 Nov 2015 16:53:54 EST ID:ogurKzAf No.14972 Ignore Report Quick Reply
Solutions are floating around via Google search on math stackexchange and other sites, you're supposed to attempt the solutions then discuss with your TA or Prof or in class the answers.
>>
Reuben Bucklesure - Wed, 25 Nov 2015 21:45:22 EST ID:QBhQLlLE No.14987 Ignore Report Quick Reply
>>14972

Sometimes this is not possible, in my class there were up to twenty problems assigned every day, to expect that many novel original proofs all the time is impossible..
>>
Archie Murdbury - Wed, 06 Jan 2016 02:44:58 EST ID:iXKR5G5E No.15014 Ignore Report Quick Reply
But the pic is related.
>>
Edwin Cocklemane - Tue, 02 Feb 2016 20:35:30 EST ID:voE+OnYz No.15036 Ignore Report Quick Reply
>Pic unrelated.
Oh, you'll be surprised annon.
>>
Albert Dublingkork - Sat, 06 Feb 2016 02:57:12 EST ID:peflw+mo No.15042 Ignore Report Quick Reply
1454745432405.jpg -(10424B / 10.18KB, 200x200) Thumbnail displayed, click image for full size.
>Pic unrelated.


Linear ODEs by Faggy Harrypadging - Wed, 03 Feb 2016 22:38:05 EST ID:0k+KCTnX No.15038 Ignore Report Reply Quick Reply
File: 1454557085767.jpg -(57503B / 56.16KB, 592x127) Thumbnail displayed, click image for full size. 57503
I don't understand how this equation is linear. Can someone explain?
>>
Lillian Sugglestock - Thu, 04 Feb 2016 02:04:38 EST ID:Zrg8t7vN No.15039 Ignore Report Quick Reply
Because sine is a function of t; if it were a function of y, then the equation would be non-linear.


Compass Math Practice by Phyllis Snodspear - Tue, 19 Jan 2016 11:58:07 EST ID:OMB8xTL7 No.15025 Ignore Report Reply Quick Reply
File: 1453222687845.jpg -(74281B / 72.54KB, 700x483) Thumbnail displayed, click image for full size. 74281
I'm going back to college after a 4 year hiatus, and I have to take the Compass test. I'm in desperate need of help on the math section since it's been about 8 years since i had to do high school math. I was wondering if any one here knows of any good sites, or maybe where to find workbooks relating to Algebra, Geometry, Precalc, and Trigonometry. I have ordered a test prep book, but I'm looking for somewhere/something to practice as much as I can.
>>
Lydia Bammerhall - Sun, 24 Jan 2016 01:37:20 EST ID:AdhSDDTT No.15032 Ignore Report Quick Reply
The no bullshit guide http://minireference.com/

However if you want to truly understand wtf is going on then Serge Lang's Basic Mathematics is what you want http://libgen.io/book/index.php?md5=576728b662199bc472c74dcbe12d3e5c
>>
Molly Murdham - Tue, 02 Feb 2016 12:02:01 EST ID:OMB8xTL7 No.15035 Ignore Report Quick Reply
>>15032
Thank you much.


Intro Adv Math Book by Clara Dirrystock - Wed, 20 Jan 2016 20:37:00 EST ID:0k+KCTnX No.15027 Ignore Report Reply Quick Reply
File: 1453340220299.jpg -(44469B / 43.43KB, 307x457) Thumbnail displayed, click image for full size. 44469
For those who've had experience with this class about proofs, do you think this book is necessary?

http://www.amazon.com/Mathematical-Proofs-Transition-Advanced-Mathematics/dp/0321797094
>>
Augustus Blollerville - Wed, 20 Jan 2016 22:23:20 EST ID:Dk8yywxc No.15028 Ignore Report Quick Reply
>>15027

If that's the book assigned for your class, read the proofs in the book. I'm not joking. There is a satisfaction received from understanding from understanding something.

I'm not familiar with that particular book, but if it is a proof based class I would HIGHLY recommending thoroughly reading the text and doing the assigned exercises. Oftentimes exams in such entry level courses come entirely from slight modifications of theorems in the text or homework problems.

Really though, get a good feel for it and read through it a few times and you will be a more clear thinking person for it. I guarantee you that time spent reading that book is time better spent than reading this website.
>>
Augustus Blollerville - Wed, 20 Jan 2016 22:25:34 EST ID:Dk8yywxc No.15029 Ignore Report Quick Reply
There was an extra "understanding" in my post but you should be able to figure it out if you're taking that sort of class
>>
Doris Grimman - Thu, 21 Jan 2016 16:47:58 EST ID:J4OUpAxW No.15030 Ignore Report Quick Reply
>>15029
Can you prove it B)

But yeah I will take your advice. Proofs are probably my most hated part of math though. Didn't realize that I was taking a whole course on them.
>>
Albert Pickridge - Thu, 21 Jan 2016 19:43:00 EST ID:Dk8yywxc No.15031 Ignore Report Quick Reply
>>15030

Proofs are the best part of math! You take that back!


Games throwing math at you... by Edward Hondermeck - Tue, 03 Nov 2015 23:19:50 EST ID:tE5uLpV5 No.14963 Ignore Report Reply Quick Reply
File: 1446610790884.jpg -(86737B / 84.70KB, 750x600) Thumbnail displayed, click image for full size. 86737
4a+7b+2c-d-10=0
9a+12b-3c+2d-25=0
4b+6c-d-11=0
2a-b+8d-41=0

I've just reinstalled Vampire: The Masquerade - Bloodlines to play the Antitribu mod. In the mod, they've added a locked door to the Tremere Chantry downtown that cannot be picked open, but instead requires a 4 digit code to open. A piece of paper is added on the table in the room you find Strauss and it has these equations on it, and I'm pretty sure that the values of the letters are going to be my 4 code digit. The problem is I have no idea how to figure them out.

Can /math/ give a gamer a helping hand?
If you can tell me the answer straight up, great, but if anybody feels like telling me how to solve the problem and others like it in the future, it'd be much appreciated.
1 posts and 1 images omitted. Click Reply to view.
>>
Thomas Piblingman - Wed, 04 Nov 2015 15:14:54 EST ID:l79SeE4Y No.14965 Ignore Report Quick Reply
What you have there are 4 linear equations (only contain variables to first power) in four unknowns, put the numbers into a matrix and perform row reduction and your solutions should pop out. But I am lazy and high right now so I'm just gonna use wolfram alpha.
a = 1, b = 1, c = 2, d = 5

http://www.wolframalpha.com/input/?i=4a%2B7b%2B2c-d-10%3D0%2C+9a%2B12b-3c%2B2d-25%3D0%2C+4b%2B6c-d-11%3D0+%2C2a-b%2B8d-41%3D0
>>
Hugh Trotbury - Fri, 01 Jan 2016 13:33:23 EST ID:QoimSJ7E No.15013 Ignore Report Quick Reply
>>14963
did u finish high school?
>>
Sidney Clommerhall - Thu, 07 Jan 2016 13:33:32 EST ID:gEBlLN+c No.15016 Ignore Report Quick Reply
>>15013

not OP but I did graduate highschool. Never learned matrix shit or anything

>>14965

so this matrix thing, Im reading about how it works and so far I understand it, at least I think I do.

given the equations OP listed my matrix should look something like this right?
2a -b 0 8d -41
0 4b 6c -d -11
4a 7b 2c d -10
9a 12b -3c 2d -25

and then I just do row reduction?
should I be including the numbers without variables in the rows? also row 2 is the row I made for 4b+6c-d-11, am I right to put a zero in the first column because there is no value of a in this equation?
>>
Oliver Bodgewell - Fri, 08 Jan 2016 15:28:42 EST ID:gEBlLN+c No.15018 Ignore Report Quick Reply
>>15016
nb but holy shit I remember formatting the fuck out of that matrix yesterday so it was legible but its totally not
>>
Nigel Drenderman - Sun, 10 Jan 2016 13:47:20 EST ID:3lJiHBSn No.15020 Ignore Report Quick Reply
it's so easy man put it in wolfram

install octave

run

A = [4 7 2 1; 9 12 -3 2; 0 4 6 1; 2 -1 9 8]
B = [10 25 11 41]

C = A\B

The result C will give you your answer in the form

C =
Comment too long. Click here to view the full text.


high thought by Nigel Drenderman - Sun, 10 Jan 2016 00:41:57 EST ID:3lJiHBSn No.15019 Ignore Report Reply Quick Reply
File: 1452404517332.gif -(641B / 641bytes, 156x80) Thumbnail displayed, click image for full size. 641
my understanding is that people don't like gravity because it's weak and it doesn't make sense why it's so weak

my thought is that maybe it isn't as weak as we say it is? a heavy object dilates time around it right? so hold that thought

if I told you i built a time machine, what are a few things you'd expect from my machine? for one, it probably consumes a lot of energy right?

maybe gravity's true power comes from being able to dilate time

maybe gravity dilates time through an unknown force?

maybe I have no understanding of general relativity at all.

if we can control gravity, we can control time and space

am i totally wrong here?
>>
Fucking Simmletore - Wed, 13 Jan 2016 08:03:43 EST ID:Zrg8t7vN No.15021 Ignore Report Quick Reply
Well, you at least seem to know what gravitational time dilation is. For those not in the know, gravitational time dilation is the effect of time ticking slower closer to sources of gravitation (relative to clocks at higher gravitational potential). This is predicted in Einstein's general theory of relativity and has been confirmed in experiment. While gravity can be thought of as a force, it is distinguished from the other forces as the curvature of spacetime itself. This means that the force you feel standing on the Earth is fundamentally the same as the force you would feel standing in a rocket ship accelerating at ~9.8 m/s^2 in microgravity.

Compared to the other forces (electromagnetism, strong force, weak force), gravity is very weak. And you're right, the reason for this is not understood. It's one of physics' unsolved mysteries called the hierarchy problem.

The only sure methods of time travel, such as orbiting close to a black hole, do indeed require immense amounts of energy e.g. the thrust required to lower and raise the spacecraft into and out of orbit around a black hole. By such means, you can only travel into the future. Time travel into the past is probably impossible.


<<Last Pages Next>>
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Report Post
Reason
Note
Please be descriptive with report notes,
this helps staff resolve issues quicker.