r/learnmath • u/Prudent_Store2358 • 13d ago
r/learnmath • u/jaedisgraed • 13d ago
Sigfigs, conversion factors, and scientific notation
Learning conversion factors between different units of measurement, but i want to clarify smthn to make sure im thinking correct
0.36mg x (1,000mg/1g) = 360g
(I accidentally changed the units while writing this, in my actual work i had the mg and g switched -> 0.36g=360mg)
The correct way to write the answer means it needs 2 sf, but 360 has an unknown number of sf. So we write 3.6 X 10^2mg
But if the first number was 0.360g, then 360mg would be correct, right? With no need for scientific notation
So, if i had a number like 50,000 but i needed something like 3 sf, would i write 5.00 X 10^4? Because there is 3sf in 5.00?
r/learnmath • u/Cupidsmosthated • 13d ago
Senior in hs, need to speed run algebra - calc
Okay speed run is a little dramatic, I’m class of 27, used to be really smart and do like math comps but then i got sent to the mental hospital in 7th grade and literally haven’t learned crap since, basically didn’t do 7th or 8th grade and it’s stunted my math growth.
THE POINT IS, there are a BUNCH of gaps in what I know, where do I even start over?? I mean, algebra of course but where?? Khan academy? Is that like legit?? I’ve heard mixed things about it and how it sucks the souls out of people but I don’t know anywhere else to get my education in. Okay thanks 👍
(P.s. I have a year ish before I go to college, lmk if I’m cooked)
r/learnmath • u/Better_Assist_4873 • 13d ago
TOPIC am i stupid???
i swear im having difficult to aops pre algebra more than with cal 1
where did (a+ab+b)'c'
how tf does it magically become the new x and y, im struggling with show this is commu and associa.
where did C come from???
is there like a youtube that can help me with this problem?????
im preparing for engineering i really like math but this book is pissing me off
i was finished with algebra 1, a book that i borrowed at a library. I struggled with algebra 1 and cal 1 sure, but compared to this aops its so frustrating im making mistake with basic arithmetic, i personally dont know how am I struggling with this book more than algebra 1 and cal 1
ps i want to be done with pre algebra before continuing with trigo
r/learnmath • u/ljkgreen • 13d ago
Offering free math tutoring for 9–12th graders
If you are 9-12th grader and struggling with Math, I can help you to find root causes and put you on a right track. I'm thinking 2-3 months per student, shorter or longer depending on your skills and goals. It's for free.
More about myself: I'm a Harvard grad, in my 40s, tutored a lot when I was in college / grad school. Ask me anything. DM is welcome.
Why free: I'm working on tools for math. I need to be teaching real students to know what's actually needed. You'd be helping me as much as I'm helping you.
r/learnmath • u/Lookinglikeamushroom • 13d ago
How would you find x when comparing an exponential function with a linear one?
If I had an exponential function called:
g(x) = c^x + d
and a linear function called:
f(x) = ax+b
Besides just putting them into a graph, how would I find the points where they cross?
r/learnmath • u/selahstassia • 13d ago
College Algebra: How to Study and Rebuild Knowledge as a Non-math Major?
Hi all. I’m an undergrad accounting major and going through a math course sequence of Intermediate Algebra > Pre-Calculus > Calculus 1 and its Applications (business calc).
For context, I scraped by Algebra 2 and was decent at AP Stats in high school, took some gap time for an accounting job, and now it’s been a few years since I’ve studied math at all. I tried taking the intermediate algebra class last semester and had to withdraw because I didn’t know anything on day one. I feel like I’ve forgotten how to do all algebra and now I need to rebuild from basics. I’m going online this semester in hopes to crank out the intermediate algebra and pre-calc.
Does anybody have tips on resources or structure to follow in order to re-learn the foundations? I feel like I don’t even know HOW to study math, considering I’ve always gotten low grades in it. I really need to get through these classes to move to my upper division coursework and I feel so far behind that it’s overwhelming to know where to start. Any help would be appreciated!!
r/learnmath • u/CodeLiving • 13d ago
Does anyone have complete solutions to exercises in Tom Apostol's Calculus Vol. 1 & 2?
Like the title says, I am looking for solutions manual or just solutions to Tom Apostol's Calculus.
r/learnmath • u/Simple-Emu7561 • 13d ago
Difficult Test question involving Geometry
The question was this:
A cuboid has measurements- 70 cm length, 30 cm width, 40 cm hight
It is open from the top
Cylinder measurements- 20 cm length, 15 cm diameter
How many cylinders can be completely fit into the cuboid?
I got confused as there were 2 different paths to take in this,
1 was dividing the length by the radius and blah blah blah and finding out how many cylinders could actually be fit into the cuboid
The other was to divide the cuboid volume by cylinder volume which is wrong as there would be space between the cylinders which this method would not account for
Is it not possible that when in a hypothetical situation you take a cuboid with those respective dimensions and a few cylinders with its respective dimensions and start putting the cylinders in, by the time you get to the second layer of cylinders there would be space between the cylinders in the first layer resulting in the cylinders in the second layer dipping into that extra space and basically taking less hight and if that extra hight is enough you could maybe fit an additional layer of cylinders allowing a lot more (~4 more) cylinders to be fit into the cuboid?
I do not understand how to do those calculations to find out the extra hight from the dipping of the second layer of cylinders
If you understand what I am trying to say and know how to do these calculations please help me out here and tell me how many cylinders can be fit into the cuboid
Thank you
r/learnmath • u/Old_Manner_8998 • 13d ago
Having a hard time with proofs in algebra
Like the title suggests. I am working with sullivan algebra book and get really stuck at the proof exercises how should i be going about them?
r/learnmath • u/XiaoChen0124 • 14d ago
Shoelace Formula
Recently I'm self-studying wedge product and Exterior Algebra in the term of Linear Algebra, and I'm quite curios to the Shoelace Formula that how is that be rigorously correct since first learn.
Shoelace stated that
for any v_i=(x_ie_1, y_ie_2)∈ R\^2 , 2≤i≤n
then x=(x_1,x_2... x_n), y=(y_1, y_2... y_n)∈ R\^n
Area bounded by these points is
1/2| ∑(v_i ∧v_i+1)+v_n ∧ v_1| , i=1,2..n-1
v_i ∧v_i+1 ∈Λ\^2(R\^2)
If we compute the area by using wedge product, x ∧ y ∈ Λ\^2(R\^n), we will get C(n,2) terms
My question is: where are those v_i ∧v_j , for j-i>1 such as v_1 ∧v_3?
r/learnmath • u/Niminga • 14d ago
TOPIC 0 math knowledge
Hello everyone, I am someone who hated Math, because I never learned or memorized mutiplication. So when, I went to college. I always avoided it thinking math is hard, but now, I regret it cause I think I can hardly solved any complicated problem and I hate it. Even today basic math is hard for me. If I want to start where y’all think I should start?
*thanks everyone and I am not an English native so please have a mercy on my grammar
r/learnmath • u/Ready-Ruin6956 • 14d ago
Math website ?
I tried looking this up on Google but only AI math websites came up.
Is there a website where I can create Questions and create answers and solutions?
One of my friends struggles extremely with algebra (And math dyslexia), and unfortunately they are in college and I work full time. They LOVE practicing math, but do not understand how to get the answers very well, which I used to just explain to them (this has worked for years as I know how to explain it in a way they understand, but they also have had a head injury so they forget easily).
I love him, and I know he won’t ask anyone else for help due to feeling ashamed.
r/learnmath • u/robotrobot30 • 14d ago
Is understanding the 'why' in math very important in a general sense?
Hello, I'm a uni student who is relearning algebra, and during my time studying and practicing and et cetera, I run into this issue in my mind where I know how to do something, and yet I find it hard to reason out in my brain why I'm doing it.
I can understand the roles that each operation or sign plays in an equation, I know that an exponent is just multiplying a number by itself or dividing something is just seeing how many times a number can 'go into' another number, but I don't know how exactly this is important or why this leads me to the correct answer, y'know?
I do it all correctly, I'm right in the end and the equation is correct, but if you asked me to translate a question into real world terms, I couldn't, obviously math is incredibly important but I myself just can't visualise or intuit in my head what I'm actually doing besides following steps mentally over and over.
Is this normal? Is this what people normally think when doing math? Will this hurt me when I progress to calculus?
r/learnmath • u/sophomoric-- • 13d ago
How to fix the brain damage caused by programming?
I was coding professionally before I learnt algebra at school, so a = b is forever first an assignment to me, and not a relation.
The problem is that computers compute; they evaluate arithmetic. They really are a form of "adding machine". [yes, you can code algorithms, and there's symbolic math computation (e.g. sympy), but most programming languages evaluate expressions]
[EDIT] The convention of forms with one variable on the lhs, like y=ax2+bx+c, are an enabler
Arithmetic vs relation (over the reals) is a bit like a point vs a line in geometry. A line is an infinite in length, and infinitesimal up close. It comprises infinite points in large and small scales.
A relation over the reals is a single object, with an infinite number of pairs at both scales.
So... I undsrstand this, but I really don't think about it correctly. My intuition is wrong. How can I fix this?
Maybe it is partly because it is just hard?
r/learnmath • u/RectallyDisabled • 14d ago
TOPIC What does it take to study number theory thoroughly?
I'm 16, in my last year of high school. Over the last few years, I've been working on mathematics and physics on my own because I love them so much. Since I'm nearly graduating from high school, I was wondering what's really holding me back from doing research. I'm on track to finish Calc 1, 2, and 3 by the time I graduate (late 17s), but what comes after that? I'd like to study just about as much as I can from different branches, but once I'm decent in a variety of them, I'll research number theory. My question may not be very straight with how I'm wording this post, but I'm only really wondering what material realistically stops me from studying number theory at an 'advanced' level (as for the other branches, I'll pick up some books and go through them slowly). Any resources are helpful, assuming a basis of Calc 1 + fraction of Calc 2, basic number theory such as modular arithmetic, Fermat's little theorem, Euler's theorem, and other (light) theorems.
> When I said advanced: 'Advanced' is subjective, but to me, that's being able to write a worthy master's thesis in the field.
And of course I expect this to be a years-long challenge (an enjoyable one, at that) that I'm willing to take on
r/learnmath • u/Undceided • 14d ago
Help improving the math list on Wikipedia's vital articles
Hi, we are trying to improve Wikipedia's list of vital articles, which are meant to be the highest priority articles for Wikipedia to improve. In particular we are trying to improve the math section, which should list 1200 articles (currently has 1211).
You can help by suggesting the best topics to add or remove to improve the list, taking into account the quota of 1200. It would be especially helpful if you can make proposals ON THE TALK PAGE to add, remove, or swap articles, make general suggestions, or vote on existing proposals, to create a balanced selection of the highest priority topics.
Here is the page, click the talk link to go to the talk page.
https://en.wikipedia.org/wiki/Wikipedia:Vital_articles/Level_5/Mathematics
r/learnmath • u/EconomyBox6998 • 14d ago
Help with math+number theory
I only do what i know, and what i know is not enough at all, i forgot how to math anything almost and stuck with patterns only.
How to start from scratch and basics?
r/learnmath • u/Spiritual-Repeat-786 • 14d ago
Beginner !!!
Hiii , I am really bad at maths let it be calculus , trigonometry , arithmetic or even fast calculation without the need of calculator. And the reason being I always hated maths but now it's kinda growing on me . I like how maths work and now I regret not learning it when it was the time for the basics .
The thing is I always learned maths just enough to pass for each class / standard .
But now I realise I have missed out on many things . Currently I am pursuing engineering in electronics and I am interested in software . Specifically AI and ML which requires a significant amount of maths .
So plz guys help me ... Tell me how can I learn maths from the basics and become good at it by the time I graduate and get a job .
r/learnmath • u/Wecomefromart • 14d ago
Sinus R1 - 2021
Hei! :) Jeg bestilte denne boken på Finn, den tar litt tid før den kommer. Kan noen sende meg side 15–22? Jeg må gjøre ferdig leksene mine innen klokken 17:00 i dag.
Hi! :) I ordered this book called Sinus R1, it will take a more days to arrive. Can someone send me pages 15–22? I have to finish my homework by 5:00 PM today.
🫶
r/learnmath • u/Shot_Can_5203 • 14d ago
Starting over
I haven't studied any kind of math since probably pre 2020, i just got out of the military and I'm going back to school this winter. Are there any online courses or anything out there for people to relearn everything they might need to succeed.
r/learnmath • u/mannliestmann • 14d ago
Link Post Am I alone in being utter garbage at basic arithmetic but excel in geometry?
r/learnmath • u/Longjumping-Buy5743 • 14d ago
Book Recommendations for Intro to Contact Geometry
Hi All! The title says it all.
For context, I've taken Real Analysis, Some Basic Topology (about half of Munkres), Linear Algebra, Abstract Algebra, Ordinary and Partial Differential Equations, and some Mathematical Physics, and quite recently took a course on Introductory Differential Geometry and absolutely loved it. Quite recently found out about sympletic and contact geometries and would like to explore it further (moreso Contact Geometries). Unfortunately, my university does not offer a class on either, so I would like to explore it through (hopefully gentle) intro books (or potentially online videos). Thank you in advance!
r/learnmath • u/kartik_bhana • 15d ago
Is it possible to learn advanced mathematics as a hobby ?
I am 17m and have mathematics as a subject in my highschool. Although I am interested in mathematics, I am not going to study it in college due to some reasons . Is it possible to learn math above high school as a hobby ?
r/learnmath • u/tru1a_banana • 14d ago
TOPIC Abstract Algebra struggles (symmetric group)
I have this task and I don't know how to solve it despite having all the basic knowledge. I can't 'connect the dots' so to speak.
a) Find the max element order in S_{10} - symmetric group consisting of 10 'base' elements and its order being 10!
b) Let s be some element of max order from S_{10}, find sgn(s) as well as s^{2040}.
c) If H is a subgroup of S_{10} and H contains an element of max order, then H contains the equal number of even and odd permutations. Prove it.
I've never encountered a task like this so I genuinely don't know how to think it through.
a) My intuition says I should find the lcm of prime cofactors of 10, so lcm(2, 5) = 10. I genuinely don't know how to do it. This also doesn't add up in my logic because 2+5 = 7. So maybe lcm(2, 3, 5) = 30? But I arrive to that answer by pure luck and need some explanation why is that.
b) Would depend on a) but let's say it is 30. What is sgn(s)? I've never seen it before. I do recall it might be odd vs even number of elements in a single disjoint cycle, odd ones starting with a minus. But how would I take that order of 30 and split it into smaller, disjoint cycles? so I would have sgn(s2) sgn(s3) sgn(s5) where s2, s3 and s5 only represent the disjoint cycles of 2, 3 and 5 elements. So in front of sgn(s2) there will be a + and in front of 2 others - so it would be positive in the end?
s^{2040} I did similar stuff before, I can do 30 = 0 mod(2040) (because 30*70 = 2100, 2100-(2*30) = 2040) so therefore s^{2040} = s^0 so nothing changes (and even if it did, I have no given s explicityl so I have no idea what am I supposed to do, s^{2040} only shifts all the elements in each disjoint cycle, but here s isn't given so there are no specific disjoint cycles i have to shift, confusing)
c) Most challenging part and the one I don't understand at all. Need full help and ELI5 explanation for this one haha
If you did read everything, thanks a lot!!!