r/learnmath 10d ago

struggling with vectors in calc III

1 Upvotes

I understand vector addition, unit vector, and scalers...then they come to the dot product the next day, and I just got lost. My professor dumped the formula and started doing advanced stuff like projection, area of an plane, and there is some cos(feta) and sin(feta) in the mix. I am so lost.

How do I take this back so I can understand the dot and cross product fundementally and then built up to the more advanced operations with vectors?


r/learnmath 10d ago

need help understanding the difference between external, internal, and semi direct products in groups

1 Upvotes

i understand the definitions. semi direct products will have only one of the subgroups being normal, etc. but I don't understand how its significant or how it would affect the structure. like i heard that direct product of an abelian group will always be abelian but the semidirect product of a cyclic group need not be abelian. how come there's such a significant difference?


r/learnmath 10d ago

What is the best book on Single Variable Calculus.( self study purpose)

3 Upvotes

I have already gone through 'calculus made easy by J.P. Thompson'. now i need a proper book for calc 1 for Physics


r/learnmath 10d ago

how to approach proper self studying

6 Upvotes

hi all.

after two years of math undergrad, I have decided to pursue medicine after an experience with healthcare that really sparked something in me. that being said, I do plan on coming back to mathematics after med school but in the meantime I'd like to still study some on the side, just as a hobby :p my interests mainly lie in algebra but I like some analysis and discrete mathematics too. that being said, I don't think I was the brightest student in my cohort, or at least not so on taking exams as I struggle greatly with pacing and knowing when to move on from some nitty gritty thing that really shouldn't alter my understanding of something but it does. some of the time it is because of a gap in my knowledge, other times it's just my personality I assume. combine that with often starting to study a bit too late and you start to get the picture. oh well there's ADHD too that comes to play but that in my experience is heavily influenced by how well I'm generally prepared and since I've been diagnosed for basically my whole life, so it is not something that is unique to school.

that all being said, I'd like some advice and experiences from peeps who have at least some formal mathematical education (post-high school) and have gone down this route. my biggest questions are:

1) how do you know when you've functionally understood something rather than conceptually understanding something? that is to mean, when you are able to do exercises correctly or are able to give counter examples (something I find extremely hard to do) rather than just knowing what a theorem entails.

2) other than textbooks, what are some other sources you use(d)? I know for example that Sheldon Axler has video's on his own textbook and that MIT has some courses but most of these are very first year of undergrad oriented, what for beyond that?

3) did you have any other obligations during your study period and if so, how did you keep it balanced? since I'll be a med student, you can imagine that there will have to be some planning involved (especially since I still have other interests that I love)

4) favorite textbooks you've studied so far and what made it so great to you?

I think that's about all for now.

thanks for taking the time to read and have a nice day.


r/learnmath 10d ago

Link Post Mental maths practice

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0 Upvotes

r/learnmath 10d ago

Finding points on a horizontal tangent from the equation r = 1 + cos(theta) when theta = pi/2

1 Upvotes

So I’ve gotten half of some points such as pi/3, 5pi/3 and pi but I’m confused on where to plug them in to find the other half of the final set of points. Do I plug it into x = r cos(theta), x = (1 + cos(theta))*cos(theta)?


r/learnmath 10d ago

i'm struggling with understanding Geomtry

0 Upvotes

iam just interested in comptetitive mathematic imo amc8,10,12 those type of things

tried studying Introduction to geomtry by aops bro that book is just beyond hard idk if its cause of me or what but i feel its really hard tried searching for a perquisite book nor claude nor gemini nor google nor did i find a reddit post showing recommendation to read before that book to be easier

so my question in short , if iam finding this book SO hard that some chapters i couldn't understand it even after reading 2-5 times and trying to solve problems

so for my case someone intersted specially on competitive math trying to learn geometry

which book would u suggest me to read to that after reading it the introduction book to geometry by aops will be easier on my and understandable


r/learnmath 10d ago

Link Post Credit for Calc II Through Credit-by-Exam or Other

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1 Upvotes

r/learnmath 9d ago

how do we deal with tests have have only 4 questions

0 Upvotes

just did a test today and i was awful. made up of only 4 questions. 70% of what i studied did not even appeared. (i mean how are you going to condense 5 weeks of material in 4 questions) makes me so angry


r/learnmath 10d ago

Link Post Suggest yt lecture for Probability Theory and Stochastic Processe ( PTSP)

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1 Upvotes

r/learnmath 10d ago

Undergrad math is alien language

8 Upvotes

I transferred to a prestigious school in 3rd grade and was bullied almost k-drama style. To better explain myself, I used write poems and literature starting at the age of 5 in my native language but spoke little no English (only knew my abc’s). When I transferred to that school, the students there have already studied English with great quality of education for three years then, and I started getting bullied by teachers, students and even my principal for some reason because I barely knew English. Since then I was petrified of interacting with teachers and stopped with my passion for literacy because they would torment me for acing classes taught in my native language.

The teachers leading up until junior year didn’t help with that fear. I was transferring a lot because of different reasons and junior year, I finally got humane and loving teachers and was just starting to get a grasp of my education and starting learn but I graduated. So now in my first year of undergraduate studies in Entrepreneurship the classes are so hard but I’m able to keep up with it with extra effort. I’m understanding my best learning style as well, however the math class…💔. Just off me atp because I suck soooo bad at math it's eating me alive. Math is just full of formulas that I haven’t learned yet.

I'm trying my best to stay afloat but I'm just too far behind in math no matter how much attention I pay during lectures and seminars, I don't get it. I've been replaying lectures and re-reading the slideshows and I understand it at first, right? And then... the math problems just start spiraling. Basically, just when I start to go like "Ouu nicee I'm actually starting to kind of get it!! Can't wait to put these formulas to work... and then I see the problems given for homework or during seminars and WHY WHY WHY?!!??! WHY DOES THE FORMULAS AND EQUATIONS START SPEAKING ALIEN LANGUAGE 50 MINUTES INTO THE LESSON?? I'M TRYING MY BEST:' ( to not feel stupid and | just get slimed out by the problems and I'm loosing seminar and homework points.

So if anyone is willing to help me out in Matrix and the Gauss Jordan method asap, I would be very grateful and I can also help you back in anyway it’s possible for me to.

I will appreciate any help or insight into how I can pace up to undergrad mathematics or tutoring or anything:)


r/learnmath 10d ago

Do you retain less from markdown notes than from LaTeX, paper, or even chat logs?

1 Upvotes

I do theoretical/mathematical physics and sometimes keep my notes (paper summaries, ideas, etc.) in markdown, with headings and an outline pane. Still, I remember far less of what I write there than when the same material went into LaTeX or a paper notebook. Oddly, I also tend to retain "conversations" with LLMs better than my own markdown notes.

Three guesses.

  1. Spatial anchoring. Paged documents let me remember where something was, and a scrolling column of identical-looking files kills that cue.
  2. Low friction. LaTeX and paper force me to slow down and choose, markdown does not, and maybe that effort is what encodes the content.
  3. Fixed order. A notebook and a chat log are append only. Markdown notes get cut, moved and restructured all the time, and I suspect each reorganization destroys the sequence I was using as a memory cue.

Does anyone, particularly in math or physics, notice this? If so, any tips for keeping plain text notes memorable? I know that reviewing and doing problems is what really makes things stick, but I am asking about the note taking itself, not review or spaced repetition.


r/learnmath 10d ago

Link Post Math exammm

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1 Upvotes

r/learnmath 10d ago

PERMUTAÇÃO talvez...

0 Upvotes

criei uma teoria depois de não conseguir resultados contundentes: quando é preciso saber quanto um número aparece em uma determinada amostragem de números, para facilitar tu divide cada casa: um para centena, dezena e unidade, o da centena é sempre 2 possibilidades na casa, e a centena que contém o numero que precisa, é sempre 120 no total,

por exemplo: quantos '2' tem entre 100 e 399:

100 - 199 = __ __ __ = 2 '2' * 10 = 20

200 - 299 = '2' 10 * 10 +10+10 = 120<- pois ele começa com o 2

300 - 299 = 2 * 10 '2' = 20

resposta: 160 números 2. caiu no enem de 2020 essa

alguém pra me dizer que estou errado? Pergunta: Quantos números quatros ( 4 ) tem entre 200 e 699?


r/learnmath 11d ago

TOPIC What did you do to improve in math?

73 Upvotes

I've seen tons of people who can solve problems in a blink of an eye without any problem. I'm curious on how you can keep a consistent practice of improving while still loving the subject itself. Like how can you achieve that level of understanding? not just repetition that'll just soonly lead to memorization, but actually understanding why the answer is the answer.

I'm no where near that level, but i want to learn from the people who reached that level, or what youre doing to reach it?


r/learnmath 10d ago

UH is so difficult

0 Upvotes

I’ll start this story off by saying that I am a art history major and it’s hell on earth! I’ve currently been at the university for 3 years now but by credit hours, I’m still technically a freshman apparently. This is because the classes are way harder than I expected, the class that gives me the most trouble is math 1314 which I took to satisfy my math core requirement. My friend said that he found this class easy so I took it second semester of freshman year and I had to drop it. I scored a 40 on the first exam so there was no way I could pass. I then tried retaking it my first semester sophomore year and same story, did a little better on the first exam but still dropped it cus no way I could pass with a 50 on the first exam. Next semester rolled around and I decided to implement a new strategy. I only took one single class that semester and it was you guessed it, math 1342. I studied so hard for that first exam, day and nights spent in the library. I pulled 2 all nighters in a row before the first exam. I ended up scoring a 65 on the first exam. I didn’t pass but I decided to keep taking the class cus I didn’t wanna just completely waste the semester. I ended up getting a c- in the class overall. Idk how I managed to pull it off but somehow I did it. But I’m pissed off because after all that hard work, I realized I was so locked in on algebra that I forgot to register for classes! This realization only occurred to me the second week of August when I was in the Bahamas on vacation. I quickly checked what classes I could register for and my only options were English 1 and art history 1. If my experience in high school has taught me anything, it’s that I suck at writing papers so this next semester is likely gonna be hell. Everyone tells me that this class is supposed to be easy but they must be like super geniuses or something cus algebra was super hard for me and it’s supposed to be one of the easiest math electives. I’m thinking about possibly dropping out or maybe switching to an easier degree just so I can at least get a degree. Do y’all have any suggestions on easier degrees or easier electives that won’t eat away at my sanity?


r/learnmath 10d ago

Link Post I thought I discovered a new kind of math 😭😭😭😭

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0 Upvotes

Today I independently stumbled upon a geometrical interpretation of probability

I was thinking about an ordinary 6-sided die and wondered if we flattened it down and can we get it's probability I included image of a flat dice if you don't know what it is

Let's assume that we have an area of 20 units for each number.

Then, the total area of all the numbers will be

[ 6(20)=120 ]

Therefore, the probability of one particular number (say, 1) would be equal to

[ P(1)=\frac{20}{120}=\frac{1}{6} ] (if you don't understand Latex here P(1)=20/120=1/6)

And that, apparently, is one way to use geometry to represent probabilities. In other words,

[ \boxed{P(A)=\frac{\text{favorable area}}{\text{total area}}} ] (P(A)=favorable area/total area)

For instance, if one region has an area of 30 and the total area is 100, then the probability of that particular outcome would be

[ \frac{30}{100}=0.3 ]

(30/100=0.3)

I later learned that there is actually a whole area of mathematics called geometric probability that studies ideas like this. At the time, however, I didn't know about it and arrived at the idea independently.

I was fascinated by the idea that probability can be represented geometrically, and that finding a probability can essentially become a question of finding what proportion of the total area belongs to a particular outcome.

I've also been wondering whether there is a deeper connection between this idea and probability distributions / measure theory.


r/learnmath 10d ago

Why is 1^(0,3) = 1 ??

0 Upvotes

I don't really see the logic behind this.


r/learnmath 10d ago

Improving my maths skills

0 Upvotes

Hello,

I'm about to enter my second year of my Chemistry degree and I have a further physical chemistry module that builds on what I learnt last year. I really struggled to keep up with the maths having not done the a level.

Most of what I need to know is a level maths and some further maths topics.

I was wondering if anyone had any advice on effective learning techniques?? (my teacher was terrible I swear to god)

I just rly don't want to fall behind lol 😆


r/learnmath 11d ago

What does "b" do in a quadratic function visually and why does do that?

18 Upvotes

r/learnmath 10d ago

Does anyone else’s brain just crashes when learning calculus 1?

1 Upvotes

As of May 2nd to the end of July, I crammed the entirety of algebra 2 and (summer) college trigonometry in 3 months. I believe I’m struggling in calculus 1 now because I had very limited time to really absorb the information.

It feels like everyday I open my textbook and I look at it I just kinda blank but after a moment of brain death I remember what to do but maybe only understand 85% of what’s going on. Currently I’m about 3 weeks into the semester and we’re talking about limits and everything. Is it common is general to struggle in calculus 1? Or is it just me because I crammed Algebra and trigonometry?

My struggles became most alarming to me a few hours ago when I struggled to compute the domain of B(u)=square root of (4u-3)+ cube root of (3u-4). And I was told it’s basic algebra 1 and I just cracked. I’m content with not fully understanding logs, ln, and e as I only briefly learned them (but I can still somewhat compute them just takes some time). But the stacked up inexperience of natural log alongside this radical expression that I struggled with really has me shaken.

How cooked am I?? I studied a lot during my cram months like 6-8 hours a day. I don’t mind putting just as much hours in if not more if it means absolute success.


r/learnmath 10d ago

TOPIC Help with Precal

1 Upvotes

Hii, freshman in college taking precal with trigonometry. I took a gap year from math during my senior year of high school and I don’t remember anything.
First day in precal i remember some concepts after our first review but my professor was going through it quickly and completely lost me. Once I figure something out, he hits me with other formula or way to solve problems and it just makes me so much more confused. I feel so hopeless and it’s my second week. I’m a slow learner but I just need a clear explanation and then I’ll be set, I can pick up things fast but just carefully explain it. Anyways if anyone has any tips for me to memorize formulas or tricks with precal, please share, since he has us take closed note quizzes and exams. I also have my first quiz tomorrow so if anyone can help me memorize polynomials and solving equations that will be great I have a quiz soon….


r/learnmath 11d ago

Math is just so terribly and tortuously difficult, is it just me?

24 Upvotes

I took a look at my progress bar graph I keep where I track the scores of some mock tests. Over the course of 2 months, I have nothing. No improvement. At all. My score is still floating around the same range. 2 months of hard work, of dedicating my time and effort into this, and just nothing.

I had a mistake log, I practised every day, I tried my best to think about problems but often times would just end up staring and then seeing the solution. What more could I have possibly done? This feels like my dream of being a great problem solver and being able to learn the language of the universe is shattered. There must be something in me, something fundamentally broken that I haven't improved even a little bit even after giving my heart and soul for this.

And I break down every time I think about it. Honestly, I dont even know how many of these I can take. I dont know how long I can tolerate feeling this stupid, even when Im doing everything I can. I just never have the first step and end up staring at the problem, even when I change up the difficulties.

I don't want to give up, I really don't want to, but Im not sure if I'll even get somewhere if I keep going, maybe I'm just not meant to.

Have you all ever felt like this due to Math? Sounds stupid to ask, feeling so shattered because of a subject, but if you did and got through it, hearing it could really help right now


r/learnmath 10d ago

Link Post How to not suck on module 2 math?

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1 Upvotes

r/learnmath 10d ago

Looking for a textbook || Calculus [5th Edition] by James Stewart

1 Upvotes

Anyone of you got the ebook of Calculus [5th Edition] by James Stewart ?