r/learnmath • • 21h ago

Determinant feels likle a niche operation but it appears at so many areas of maths I just dont undersaatnd or fathom it.

76 Upvotes

Like how does a niche operation designed to number a matrix such an importn concept. Like it feels so niche and unique but this function is there everywhere please help me conceptualise it.

Thanks in advance!


r/learnmath • • 8h ago

struggling with Real Analysis

27 Upvotes

Currently a second year undergrad student taking real analysis. This is my first proof based math class and I have not taken discrete maths before either. I’ve already taken up to calc three and linear algebra, did pretty well in them.

The professor is using Understanding Analysis by Abbott, and the lectures mostly make sense to me. However, his problem sets are very very long and do not follow the textbook questions. He seems to come up with them from his brain…and he posts them every Saturday..which is also great.

I find myself really struggling to know what steps to take and where to go after reading a question asking to prove or show something. This makes me very worried for future exams.

Any and all advice would be really appreciated!


r/learnmath • • 15h ago

Any free websites/apps that could help?

11 Upvotes

Hii everyone. So, my parents have failed to put me into any sort of school basically my whole life (never tried homeschooling as well). Now I'm nineteen and I really don't understand any form of math, even the easiest questions, and I've been really wanting to get into learning it, so if anyone has any recommendations on videos, websites, apps. Anything. I would greatly appreciate it :D !! The easier it is to understand, the better (I have a learning disability.)


r/learnmath • • 16h ago

Is there a book or a series of videos that you recommend for missing fundamentals for Algebra?

5 Upvotes

tldr: I really want to get bridge mathematical gaps after struggling in high school after seeing how it can be applied, stuck with many holes in my algebraic knowledge and would like any recommendations for this specific dilemma. Thank you!

I'm currently starting my bachelors degree in Computer Science, I have a deep love for games and want to dabble behind the scenes with game engines, 3D graphics and such. I'm well aware mathematics play a large role in this topic such as calculus and linear algebra for the algorithms and physics of certain mechanics.

My excitement has intertwined with fear due to my previous experiences in high school so long ago, especially with my overall disinterest of it general math back then that's caused gaps, I barely survived it in high school. Now that I actually have something to apply and learn math for, it excites me, but I feel slightly discouraged and not good enough for it.. especially haven’t fully grasped algebra concepts well. I also really struggled to take math notes!

Granted, I've realized I had a learning disability when I first started college, which makes a lot of sense as I can name so many points in my education where I would simply just zone out, but it doesn’t make me feel better about myself. I now have a few motivators; I want to heal the inner child in me and take control of my education after years of being frustrated from looking at my math homework. Im seeing math in such a different light when it is applicable, implementing cool, game physics mechanics looks really exciting. And of course.. to get my degree haha. Any recommendations would be appreciated! I could have searched this up, but I wanted to gather some anecdotal experience from others on here, especially if any of you have an experience similar to mine. :)


r/learnmath • • 23h ago

Serge Lang's Basic Mathematics book for Precalculus

3 Upvotes

Hey guys, I am working through Lang's Basic Mathematics and was hoping to find people in the same boat to discuss concepts with, clear up doubts and bounce ideas off of. If anybody is interested, feel free to DM me. Doesn't matter what point you're at in the book, we can still find a way to make it productive for each of us.
My intention is to develop a rigorous understanding of precalculus before proceeding to undergrad calculus, so anybody looking at Gelfand's 3 books is also welcome to reach out.


r/learnmath • • 1h ago

Binomial series statement in Spivak - need to exclude trivial case of x = 0 ?

• Upvotes

In the chapter on "Infinite Series", one of the problems is to prove the following:

(1+x)^a = \sum_{k=0}^{\infty} [\binom{a}{k} x^k] for |x| < 1, for any a

Surely, this is not true for x = 0 as the LHS is 1 and the RHS is 0. So, does one not need the caveat that x \neq 0 ?

Additionally, what is the definition of \binom{a}{k} if a is fractional? Is it just a placeholder for a(a-1)...(a-k+1)/k! ?

I attach an image of the problem in the comments.


r/learnmath • • 3h ago

TOPIC How to build advanced proof writing skill

3 Upvotes

So I just finished book of proof by Richard hammack which is a book on how to Write proof (duh) whith most of the problem solved including a lot of hard one ,but now I'm bit lost on where to move on to develop advanced proof writing skill so I can tackle subject like topology n' abstract algebra cuz that's why I'm trying to learn those skill in the first place so it would be cool if u could give me some suggestions (I'm a self-taught idk if this info matter) on how to develop those skill ty in advance


r/learnmath • • 6h ago

Link Post Lean-verified unconditional lower bound on the proportion of simple zeros on the critical line: 0.673401159168

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2 Upvotes

r/learnmath • • 10h ago

Struggling in first proof writing class. Advice?

2 Upvotes

I'm a college student a few weeks into an intro to proofs course (logic, sets, induction, relations, functions, etc). I've seen proofs before, but I'm having a hard time adjusting to working with arbitrary elements and figuring out how to put proofs together. For example, when I'm asked to show two sets are equal, I understand the definitions but can't figure out where to start.

The class is flipped, so I feel like I'm mostly teaching myself from the instructor's notes. I'm worried about falling behind and want to make progress while there is still time. What helped you get through your first proof-based class? Any study habits, ways of thinking, or resources that you'd recommend?


r/learnmath • • 14h ago

ISO a Real Analysis tutor

2 Upvotes

Looking for someone to help me with an undergraduate Real Analysis math course.

Willing to pay but i’m also a student so please be reasonable.

**Edit:

Thank you all for your willingness to help! I have found someone from this post and am no longer looking for a tutor :)


r/learnmath • • 16h ago

I’m fully confused about Disjunctive Normal Forms

2 Upvotes

The statement : Show that every predicate in two variables can be presented as the composition of the elmentary predicates AND , OR and Negation.
I understood that steps where
1. Truth rows are constructed purely from AND and NOT
2. False row is achieved by combining the expression in 1 with OR.

How does it then “prove” that the mechanism works for every predicate?


r/learnmath • • 16h ago

I Need Help!!!! (COMPLEX NUMBERS)

2 Upvotes

I have been studying complex numbers for the past couple of months (I'd say I'm fairly confident with them at this point).

The one thing that drives me crazy about this topic is how you can solve those long Euclidean geometry and trigonometry problems in what, like, minutes, and that too with such insane elegance.

So I just wanted to find more geometry and trig problems of this kind, but I couldn't find any good material anywhere. I just wanted some suggestions about what resources I should refer to.

BTW, I'm just 16, so don't expect me to know very high-level stuff, but you can expect me to have a solid foundation in algebra and geometry.

(English isn't my first language btw, so excuse any errors lol.)


r/learnmath • • 17h ago

Free interactive tool for practicing math from foundations to Olympiad level (EquaRank)

2 Upvotes

Hi r/learnmath,

A common struggle I’ve seen (and experienced myself) when learning mathematics is the gap between reading theory and actually solving enough problems to build true intuition.

Watching videos or reading textbooks gives an illusion of competence, but you only master math when you struggle through problems yourself. The problem is that finding quality problems organized by difficulty with instant feedback is surprisingly tedious.

To help solve this, we created **[EquaRank](https://www.equarank.com)\*\*.

### What makes it different:

- **No multiple-choice guessing:** You actually enter your solution as a mathematical expression. The engine tests symbolic equivalence, so any algebraically valid form of the correct answer is accepted.

- **Structured Knowledge Graph:** Instead of jumping randomly between topics, you follow an interconnected roadmap. Master prerequisites before unlocking harder topics like modular arithmetic, linear algebra, or multivariable calculus.

- **Wide difficulty spectrum:** Over 8,000 problems starting from middle school foundations up to international math competition levels.

- **Weak-spot training:** The system tracks which specific concepts you struggle with and serves targeted practice to fill those gaps.

It’s completely free to register and practice: **https://www.equarank.com\*\*

If you're currently studying for high school exams, college STEM courses, or just self-studying math for fun, give it a try. Any suggestions on topics you'd like more problems in are very welcome!


r/learnmath • • 21h ago

Please help me!

2 Upvotes

Okay, so I have this sum:

"A printer numbers the pages of a book starting with 1 and uses 3189 digits in all. How many pages the book have?

Options:

a) 1074

b) 1075

c) 1000

d) None of the above"

My solution:

"The total number of pages have 3189 digits. (given)

⇒ the number of combinations= 9*10³¹⁸⁸.

∴ The total number of numbers= 9*10³¹⁸⁸*3189!

∴d) None of the above"

The Book's Solution:

"1 digit numbers have 9 digits (9 numbers)

2 digit numbers have 180 digits (90 numbers)

3 digit numbers have 2700 digits (900 numbers)

4 digit numbers have 300 digits (75 numbers)

[since total number of digits is 3189, hence

Number of digits for 4 digit numbers

=3189-(9+180+27000)= 300]

Total number of pages

= 9 +90 +900 +75= 1074"

So, according to them, the correct answer is a) 1074, but for me its d) None of the above.

Please help

Note: The solution of the book is almost verbatim, with marginal changes in the format.


r/learnmath • • 22h ago

I feel like I am getting worse on math

2 Upvotes

Generally, my friends think I am good at math. But I think I am bad at it, even when I get good grades, it feels like 'by luck' to me. MY confidence is really dropping. It's quite evident that I am not necessarily bad at math. This was my performance last year:
92%, 80%, 94%, 45%, 65%, 96%
And this is my performance this year:
96%, 81.333%

Today I attended another exam- and this is the most important of all. And this is where I messed up badly. I'm estimating 60-70% this time. I needed at least 80% to keep my grades intact, but now it got harder for me.

I keep failing to solve several of the problems, and seeing my friends effortlessly solve the problems, For more context, I secured top 13% in last exam this year, and previous years grades placed me in 99th percentile (all subjects).

I got 45% and 65% in 2 tests last year, due to lackage in geometry and vector-so after that, I fully mastered those chapters. But in geometry (coordinate), I still keep messing up known formulas when applying, and plus-minus of course.

My main weakness is time management, anxiety and nervousness I think which worsens my natural performance. Amongst the disliked chapters are- Trigonometry (Quadrant equation solving), Coordinate Geometry (Reason stated).

Please advise me what I can do to overcome these issues.


r/learnmath • • 23h ago

Any resources to learn DISCRETE MATH???

2 Upvotes

.


r/learnmath • • 42m ago

TOPIC For those who used to be bad at math, how did you make an academic comeback?

• Upvotes

I've struggled with math for years, and sometimes I feel like my foundations are way weaker than they should be.

For those of you who used to be really bad at math but eventually improved a lot, what did you do differently? Did you start over from the basics, change your study habits, or approach the subject differently?

I'd love to hear your experiences and what actually worked for you.


r/learnmath • • 4h ago

test on series in 2 weeks. very scared. any resources

1 Upvotes

Im in calculus 2. first year. and we're having a test on series and sequences in almost exactly 2 weeks. on the last test i made a bunch of stupid mistakes and got a 57.5. now my grade is a 74.5. i really need to get at least a B (80%) overall and there are 3 tests left including the final (all 15%, except final which is 25%.... rest is HW and quizzes and class participation which im not very worried about)

i started studying ahead of the class so ive already learned all the series tests. did a practice test today by looking at a previous exam and it went terribly. im not prepared at all. i cant fail again but i feel like im going to. its only my first semester and i feel like dropping out. i thought i was smart but i feel like a complete idiot. wjat do i do

any recommended resources??? i have already used pauls math notes. Using previous exams/lecture notes. what else


r/learnmath • • 5h ago

RESOLVED how to factor trinomials using substitution (my book does it in a weird way i cant find online)

1 Upvotes

in general ive been having trouble factoring polynomials because the steps dont seem to mean anything, and it seems more like simplifying than factoring even though i guess those are similar?

but onto more pressing matters. my book factors trinomials with substitution as such:
consider trinomial 3x^2 - 2x - 8
step 1: multiply ax^2 + bx + c by a to transform x^2 into (ax)^2.

i dont understand why we do this, no other video has done this before. i'd understand this step if the 3x^2 term was to equal 3(3x^2) which i think would be 9x^2 but it doesn't equal that. in general, i dont know what "transform x^2 into (ax)^2" really means. or why we do this when other videos have a common binomial substitution which i can do easily. after the supposed multiplication of 3 to every term, we have:

(3x)^2 - 2(3x) - 24
(Why isn't 2(3x) just 6x???????? why is - 24 not -24x since in some places we multiply by 3x and others by 3??)

replace ax with a variable p. p = ax.

we now have p^2 - 2p - 24. the typical factoring commences where c = pq and b = p + q.

we now have (p - 6)(p + 4). we substitute ax back into p.

(3x - 6)(3x + 4)

3(x - 2)(3x + 4) factoring out common factors we end up with (x - 2)(3x + 4) im under the impression the common factor of the second binomial was 1 which i've never seen before. but that doesn't make sense as what did we divide 2 by then?

and then since we started by multiplying the trinomial by a , we must divide by a, and this obviously doesn't make sense to me as someone not behind the reason we multiplied by a. the answer is (x - 2)(3x + 4)

we have the easier and obvious method of AC grouping (i dont get it but its consistent so whatever) but we also have substitution and im scared i might get a question asking me to factor by substitution specifically in our upcoming midterm.

help to understand or other resources much appreciated.


r/learnmath • • 7h ago

Learning mechanics

1 Upvotes

Hello, I'm a first year university student and my course doesn't offer any mechanics modules so I was wondering what specifics I should cover (classical mechanics, Newtonian, etc.) and in which order. Also any suggestions on resources.


r/learnmath • • 9h ago

help with a homework question about logarithms

1 Upvotes

I can't seem to understand this one problem. could somebody help me solve for X?

(lnx)^3-ln(x^25)=0


r/learnmath • • 18h ago

TOPIC What does business calculus entail, and how can I prepare?

1 Upvotes

Hello! You may have seen my post here before about struggling with calculus, but now I have a much better grasp on it. After getting a 52 on one test (😬), I have now gotten an 84 and a 90 on my other tests. I still have some work to do, but my math future is looking brighter.

Anyways, I plan on majoring in accounting in college. After looking at several course catalogs, business calculus is a very common required course for my major.

I think it’s more practical applications of calculus, but has anyone here taken a class like this? What resources helped you?


r/learnmath • • 19h ago

How do I improve at math?

1 Upvotes

I wanna improve at my mathematics and genuinely understand the science behind it. At first I thought that my foundations of math was above average but after taking a scholarship test today and bombing it, I then realized how far I am at math. The topics of the scholarship was mathematics and ESAS and I genuinely only answered like a total of 11 questions at most over 30 and it shattered my self understanding of math. I don't consider myself to be dumb at math because I have high grades on my senior highschool so I only reviewed the past topics I know and didn't really prepare for a problem solving type of math because I thought that the scholarship exam would only cover my knowledge only senior high level math, now I realize that my last school didn't really teach me to understand math. I realized I only know math I don't really understand it. That scholarship was supposed to help me and my family's financial situation but I can't do anything about it anymore, I just wanna be better at math and science because I'm currently studying BS in Electrical Engineering and wanna improve myself so when an opportunity arises again I can prepare.


r/learnmath • • 20h ago

Link Post How do you help a child who memorizes math rules but doesn't understand them?

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1 Upvotes

r/learnmath • • 20h ago

help?

1 Upvotes

alright so basically we have 1 over x²+1

we make shure that x can't be equal to 1 or -1 stay with but why don't we do this

√x²≠√-1

x≠i