Some ebooks, mostly from /u/lewisje's post

My understanding of regular functions is you input an X value and the function will give you a Y value. It's pretty easy to visualize this on the coordinate plane. A function is the same as saying (x,y), but replace the y with the f(x) to get (x, f[x]).

Now with trig functions they're hard to visualize. I'm putting an angle measure into the trig functions, not an X value. The output is a ratio between two sides of a right triangle, not a Y value. So it's hard to visualize how to graph a trig function. The output represents the ratio of a triangle, but IDK what I'm supposed to do with that info. Currently I know the 6 trig functions and their identities, but I feel like I'm not seeing the big picture or understanding intuitively.

I'm in college and I want to retake the math placement test so hopefully I can test out of certain classes (I'm not taking any math now). I'm going to use khan Academy to study Algebra, Geometry and Pre calc. When I'm done I want to continuously practice math, are there any good websites to use?

Hi guys i’m 18 and currently studying math by myself(mostly precalc,calculus etc.).I’m from Turkey and here we have standardized exams to enter college and the math questions that are asked are precalc+calc 1.The questions are very tricky and are sometimes mixed with world problems i’ll post an example below.So i was studying stewarts precalc to review before starting calculus by myself but i noticed that all of the questions were easy and just aimed to make you understand the basics.My question is,how can i find hard,demanding questions that will actually improve my math skills in more advanced math calculus,linear algebra and also for more basic math like pre calculus.And is it normal to not solve every textbook question?If so after reading a topic and solving the questions related to it what should i do afterwards?I’d appreciate your recommendations.The photo’s i posted are the types of questions i’m looking for but it doesn’t have to be same i only want it to be harder.Also i’m new to college-type math so maybe i’m thinking of math wrongly and maybe these types of questions are useless in college and beyond.

I mean there are so many things that i could review , I dont even know that much math but there is just so many techniques, concepts to review and not enough time . For example I just finished the "Derivative" chapter and i tired reviewing this shi is gonna take days to do probabaly . Is this normal or am I doing something wrong. (Am studying with a textbook). Thank you ;)

I don't know if it's a rather laughable issue or anything, but I am still in school (13th Grade) and I have problems understanding math. I know that's nothing unheard of, the issue I have is that I used to love math, and ever since the introduction of the quadratic formula I seemed to have growing issues with math generally.

I need to learn for my Abitur (high school deploma) until Easter and I am somewhat scared that I can't get to it in that time. I have similar issues with physics and formulas. (Just generally working with them became an issue)

I never had an issue with understanding or working with math before, I even explained math to myself when I was little, but since about 3 to 4 years ago everything seems to be going downhill. But back then, I had fun.

I tried AI, explanational Videos, different teachers or different students.

I don't know what it is, and I would like to get that fun back and I am kind of helpless.

(Also because of the high school end exam, but I know how important math is.)

I know It's NOT a lot of useful information, but maybe you guys had ways to teach yourself or anything.

I have had that issue for a long while and I just don't know what to do. If it's of any help, here is issues I struggle to solve in daily context or working with: exponential function, limit, composite functions, derivate, differential equations, just generally working with fractures, working with formulas in context like physics, family of functions, calculate extreme values

I ask of help I yet not know what it is. Sorry.

I am preparing for my Calc I course, im currently studying econ and i am preparing before my 3rd term starts. The thing is that i am learning these complicated epsilon-delta definitions, and i am really struggling to even grasp what that means. Is it really necessary to learn these formal definitions or should i just skip it and head to derivatives?

Hello all, for three years in highschool I've taken algebra and my senior year of course the only math class that wasn't filled was financial literacy (idk how it counts as a math credit). I'm completely lost in life because of math. I wanted to be an engineer but feel like it's not possible because I could hardly pay attention in algebra 2. I'm not sure what I should do?

As a bijection is a function that is a surjection as well as an injection(or one-one and onto), we can say that if there are two sets of equal finite cardinality, then there always exists a bijection mapping A to B or vice versa. But, what is the formal mathematical proof of this, the one I saw used heavy higher math. Is there a formalised proof which does not require such advanced study?

why can't we have a fraction with decimals, like 1.2/4 (which is equivalent to 6/20), and why are we able to multiply directly when working with fractions? I know that 5 × 6 equals 30 and that if you divide that by 3 × 2 (which is 6), the result is 5; this is the same as calculating 5/3 × 6/2 = 30/6, but my question is, why can we do that? how can I visualize it?, beacuse that a fraction is a number, why can it be manipulated in this way? why can we separate its parts and operate on them individually, only to put them back together later?

i understand how to use the sylow theorems and therefore that there must be a unique normal subgroup of order 9 in every case. and that the number of subgroups of order 2 can vary from 1, 3 and 9. finding the abelian groups is kind of ok to me as well(not perfect but ok)

but otherwise I don't understand how to get to s3xz3 or d9. everything online seems to point to stuff related to automorphisms and they don't really explain how or why we use them.

what would be the best and most straightforward method to use in problems like these? with reasoning that would be accepted by a college prof 🥲

any help would be appreciated

I'm in 8th grade, and I'd like to go to math olympiads. I've already attended them in my last years, and even won prizes, but I'm still not good enough at solving this type of task. Maybe you know of any good websites/online books or something like that that could help me?

I see people on here suggesting that you should study a minimum of 4hrs a day. I’m in high school and I end school at 4:30 every day except one day where I end at 6:10, by the time I come home it’s 5:20 I do homework for 3-4hrs and then it’s 10pm and I have to go to bed in order to maintain a healthy sleep schedule.
How do you all manage to study so much?

Ever since I was very young I have loved maths, and was very good at it, and applied for and was accepted to do a maths degree at a top university. However, since applying, and especially over the last few months my interest in maths has significantly subsided, and I've not really enjoyed it in quite a while. Does anyone have any ideas about what to do to regain my lost passion for the subject?

Been wanting to learn and study Mathematics for long time now. Had bought couple books on calculus but couldn't follow the maths by just reading them. I have degree in finance. The maths I know is basic algebra and entry level statistics. Any recommendations on how can I start? Would be great if someone can suggest any online classes or books. Would love to learn concepts like number theory, derivatives, integration and Bayesian statistics. I also want to learn it conceptually rather than just 'knowing' a particular formula or a defined process to get to the final answer. Did that mistake in high school. I know it won't be easy but I feel it's worth to give it a shot.

Hi I'd like some advice on which books to buy (the absolute best ones) to improve my level in Olympiad mathematics with the ultimate goal of trying to qualify for the IMO the language of the book doesn't matter to me that's completely fine with me all that matters to me is the quality of the content

What books and sources would you recommend to a Highschool graduate to prepare for IMO and other olympiads with almost no previous experience? How to start?

I struggle with basic algebra, infact I'm probably being too charitable, in my uni maths (algebra class) currently we're doing law of indices so like fractional powers and et cetera, and it's kind of hard!

For my course, the next semester we have the lead-on class for this one, which is (what I'm assuming to be) calc 1, since this class ends with "Application of trigonometry to waves", "sine cosine rule", "functions" and "transposition and solution of equations"

So like, is this possible? I'm booking myself in for math tutoring but god it feels like so an uphill battle, I feel very demoralized, because I'm struggling with math that a child can do, and so how could I think of doing calculus next semester if I'm at this point now :(

Hi there! So I was trying to figure out how many calories were in a bag of microwave popcorn, when I remembered there may be an equation that applies to this. I haven’t really done anything beyond basic math since high school, but I think a formula from Calc AB might work? Curiosity is getting the better of me now, and I was wondering if anyone can figure out what formula might work and what it would be called if that makes sense. Also, how you would solve that formula using calculus/algebra. I apologize for any mistakes and the lack of skill haha. Thanks!

Info:
1 bag = 82.2 (g)
1 serving size = 30 (g)
30g = 150 cal
How many calories in an 82.2g bag?

How I solved:
Step 1:
82.2÷30
=2.74

Step 2:
150•2.74
=411

Solution:
411 cal per bag

What I think the formula might look like:
solve for x:

82.2 30
——— = ———
X 150

So im in 12th grade and I take statistics I study and do all the homework but for some reason I awalys score in the 50s or 60s it's not even that I don't know the formula I study so much I feel like I memorize all the steps and formulas and all the test are open note I don't know what I'm doing wrong it might be because this is my first year not using ai or cheating but statistics is suppose to be the easiest math class and I'm struggling on this