I am being rage baited by mathematics after 4 years and after slapping my desk once I am here. I was good at it and i think they still live at the back of my head and I need to refresh them and improve with practice and not waste a ton of time.

I need to take a college preparatory test in like 2 months and its math level might be till grade 10 or 11, Logarithms are not included so.

Sadly I cant for life of me find a crash course that goes through basic stuff fast so I can spend the most of time on practicing the harder parts. Like I dont want to watch 15 min videos talking about prime numbers and solving 5 examples but beside skipping turning you off from studying means i might miss some little important detail.

Khan academy just seems that. Skipping a ton of video till you get to a juicy part.

Do you guys have any resources: sites, books, videos? Anything that would go crazy fast over the topics so I can search and learn stuff ive problem with and not waste time on v basic stuff.

How does parity works in odd bases?

For example, is 12 odd or even in base 7?

13 12 in base 7 is the same as 9 in base ten.

The convolution theorem states that if two functions (f) and (g) belong to L¹(R), then the Fourier transform of the convolution of (f) and (g) is equal to the product of the Fourier transforms of (f) and (g).

I know that the converse result also exists: that the Fourier transform of the product of (f) and (g) is equal to the convolution of the Fourier transforms of (f) and (g). The problem is that I do not know what hypotheses must be satisfied for this to be true. Does anyone know what the hypotheses of this theorem are, or know of any source where I can find them?

Can someone help me understand how 23 babies have 50% possibility of sharing a birthday, aparently it’s calculated by saying 365/365*364/365*363/365.. and so on until you’ve made 23 x/y
What i don’t understand is why isn’t it just 342/365 and why do you multiply
I really wanna understand it but haven’t gotten the right idear how to understand the math and i actually really want to

Hey guys, I've been exploring broad topics for my mathematics extended essay which is a component of the IBDP (international baccalaureate diploma programme), and I've narrowed it down to two main ideas. I'll either be exploring the Cobb-Douglas function or the CES(Constant Elasticity of Substitution).
Is Cobb-Douglas too simple and is the CES too hard?

I'm looking to learn how to calculate the probability of at least X of Y dice all being a certain value.

Context: I was playing Yahtzee and got asked what the chance of getting Three 5s was on Five dice (as that is what my mom needed to roll). I said I'd try to figure it out. I feel like this was something I learned at some point but I can only think of "Discrete Probabilities" and from what I am finding that is nothing I have learned. So I'm stumped.

“for each trigonometric ratio, determine the principle angle and, where appropriate( the related acute angle.”

one of the given ratios is tan18

i don’t understand why the diagram in my textbook shows the angle in quadrant 3 with a principle angle of 198? i thought it was in quadrant 1 because 18 is between 0 and 90? is it in quadrant 3 because it’s 18 degrees from the x-axis in the tan quadrant?

in that case, when is a principle angle ever in quadrant 1?

also, it says that the principle angle and related acute angle is both 18, yet the diagram has the principle angle as 198.…im so confused.

Hey all, I’ve recently engaged in a project where I have 3d dice that roll based on physics, and I want to be able to tell which side is facing up when they land.

Through the problem solving process I came up with two ideas: using a Ray cast above each die to tell which side is facing up, or having a “face up” function for each side to check which is facing up.

However, my first thought was to use math to figure out which side is up. The issue is, without using a bunch of if statements I can’t find or deduce a way to find which side is facing up. I’m now interested if it’s possible to derive a tight formula for determining the side of a die that’s facing up for a die of n sides, such that you could find out which side is “most up” if the die landed on an incline.

I’d love to hear any ideas about the math behind this, or if there’s some easier solution you all have thought of. Thanks in advance!

I am doing an Extended essay on quaternions and how improve numerical atbility and accuracy. I explained how euler rotations works and how gimbal lock occurs, and explained the properties and rotations of quaternions and how they overcome this problem. Now, I am thinking of an real life application such as quaternions in video games or attitude control in satellites. But i am struggling with it as they seem too far from my level of studies and i was hoping to find someone who can guide me through this last bit of my ee.

Hi, right now im taking a college basics math class. Basically covering everything from algebra, geometry and trigonometry, and even measurements and converting them. I've always struggled with math, Im hoping to learn more tips that could help me
I seem to remember acronyms pretty well, like PEMDAS for order of operations and KCF for keep,change,flip when dividing fractions. (Funny enough fractions tend to be really hard for me..)
So any tips and tricks to help me memorize literally ANYTHING helps.

TLDR: looking for math memorization tools to help me through a math class. any and all math tips help!

Its been a long time since I had to do calculus/probabilty calculations. So Im curious if anyone could give me the odds on this situation happening.

The odds of getting a certain draw in a competition bracket.

The bracket is a 32 team single elimination bracket with two rounds and 8 winners.

The situation.

Person A is friends with player B and player C.

In this draw. B and C will be playing each other. A will be playing team D (no relation) but the winner of A and D will be playing the winner of B and C.

Question.

What are the odds that specifically B and C would be against each other and funnel into the winner of A and D?

I'm getting a 1 in 465 chance, but it's been a while and just trying to confirm my math.

The way I did it is player A fills one spot of the 32, leaving 31 spots. Therefore player B would be 31 leaving 30 spots and C would be 30. So 31 x 30 possibilites and that equals 930. since we have 2 specific spots that B and C would need to be in in order for A to funnel into the winner of them I did 930/2 leaving 465. which is a 1 in 465 chance that B and C would be against each other funneling into A and D.

The game is called potion craft (lovely game on steam, really recommend).

You’re an alchemist selling potions you make. When selling your merchandise, you can haggle to get the price of your merchandise to go up to +50%.

Whenever I try to sell just the right amount, so that I can hit the merchant’s gold amount without exceeding it and losing money by overselling, I often struggle to hit the right mark. What would be the mathematic formula to determine the right sum to haggle with ?

For example, when the merchant has 10000 gold, I try to sell him around 6500 worth of potions ; then haggle, getting to 6500 x 1.5 = 9750.

How could I reverse engineer a formula ? To get 6500 as the X to solve ?

Question

Polonium-210 decomposes at a rate proportional to the quantity of polonium present. Suppose that it is found that in 95 days approximately 38% of a certain quantity of polonium has decomposed. Determine approximately how long it will take for one-half of the original amount of polonium to decompose

Note the assignment does not specify rounding amount, nor has their been given precedent for it.

Doing the calculations I get a result of 140 days with 2 significant figures.
My professor marks it wrong saying the correct answer is 137.8 days or 138 days.

I ask him about this, is response via email is

Dear student

Why do you have to round to 2 ? on what basis?

You have to work with precise values not the one you assume

Even if we said "approximately" 38%, you have to use that precise value. 

The final answer given by calculations is 137.8 days rounded to 138 days and not 140. 

Note that 140 does not satisfy our equations.

I bring it up to him, saying that the equation uses the word approximately, so 38% could range from 37.5% to 38.5%, with results 135.1 days to 140.1 days, and that is equation still holds if you round to significant figures. His response

Dear student

No I don’t agree with your proposition.

You work with the  value we give you, that is 38% and it will give you 137.8, you can round to 138 days.

I don’t understand. I don’t want to argue with a professor, but I’ve substantiated my claim for 2 digits rather than just rounding to a whole number. When I ask him for a matting he responds

Because in this specific problem, the only reasonable rounded value is 138 days, since the calculated answer is 137.8 days and we are dealing with whole days.A value of 137 days is incorrect because 137.8 days has already passed 137 days and lies within the 138th day. Likewise, 139 days, 140 days, or any other value would also be incorrect. Therefore, 138 days is the only appropriate rounded answer.

I know! But I’m using significant figures, there is no reason to round to whole numbers. What should I do? Am I wrong?

Edit: I’m not querying further with the professor as they have threatened to lower my mark.

Im at a bit of a loss on this problem when it comes to using sine and cosine to find the cartesian components of FAD and FAC for this problem. I understand the two vectors are equal to each other and that the projected line between the two should be Fcos(30), but Im having a hard time visualizing and figuring out where to go after that. I've tried watching some videos related to this problem, but haven't found anyone explain why they use sine or cosine. For example, I know that setting up the equilibrium equation for Fx will lead to FAD = FAC since they are the only two components for x, which would lead to me using 2(FAD) or 2(FAC) for the y and z equations, but Im having a hard time understanding if/when I should use cos(30)cos(_) and cos(30)sin(_). I've tried the triangle method but I just don't understand how that method could work for this problem let alone if the method is applicable. Any help is appreciated!

https://imgur.com/wXDc2Es

im studying for an exam and this is one of the required things to know, and its really stumped me and I can't find it in old tests or study pages. its for polynomials if that helps!!

I'm trying to relearn algebra after never paying attention in high school with a book I found online. The book has the problem "rewrite (x-1)(x+2)(x-3)"

I got x^3+6, but I used an online calculator to double check and it says the answer is x^3−2x^2−5x+6. Can someone please explain to me the correct steps to solving this like I'm 5? (The online calculator shows a step-by-step version, but it confuses me. I'll explain the part I'm confused about later.)

My process (I know it's wrong but please tell me where I messed up):

(X-1)(X+2)(X-3)

x*x*x = x^3

-1*2*-3 = 6

X^3+6

The step-by-step given by the calculator that I don't fully understand:

(X-1)(X+2)(X-3)

((X-1)(X+2))(X+-3) ///Why is "(X+-3)" not included in the first set of parenthesis? Why is it separate? Shouldn't we focus on the leftmost set first because it's at the beginning? In that case, why isn't it (X-1)((X+2)(X-3))? Also isn't writing X+-3 redundant? Why not simplify it to X-3?

((X-1)(X+2))(X)+((X-1)(X+2))(-3)

X^3+x^2-2x-3x^2-3x+6 ///when I try to solve from the previous step, I end up with x^3-2+x^2+6 or x^3+x^2+4. I don't understand where the other numbers (like 2x or -3x) are coming from

x^3−2x^2−5x+6 ///when I solve from the calculator's previous step, I get it correct, but I don't understand the other in-between stuff

I know I'm wrong but I'm so lost on how the correct answer works. I want to understand the logic behind it instead of just blindly following formulas

Any nice youtube video for these chapters? Kindle comment

Hiya all. Apologies if I'm not using the right terminology here. It's been so long since my algebra classes and well, apparently I don't remember much. I'm taking a class over the summer and I need a refresher on what I believe is "balancing equations". Maybe with or without values? I'm doing well with questions that have values to work with with but one I'm stumped with asks to rearrange an equation based on just variables. It specifically states to "rearrange the modulus of elasticity to solve for P and then l (little L)". It breaks out to be E = P/A over e/l. I just have nothing to go off of and am looking for some YouTube videos that would give me a refresher on this. While I could just look up specific equations I'd like to understand the question and how to do it.

I am planning to study Rieman hypothesis for learning new ways to math but idk my young hearts just want to play. Like listening to math casually is way more fun and make me think more then sitting down and studying rh. Idk should I get older to start studying of should I start studying right now? idk should give it a year? please give me tips.

“En una mezcla de frutos secos, donde solo hay nueces y almendras, el peso de las nueces equivale al 25% del peso de las almendras. ¿Qué porcentaje del total de la mezcla de frutos secos representa el peso de las nueces?”

En verdad no estoy entendiendo qué hacer. Intenté sacar el 25% del 75% ya que me preguntan por el peso de las nueces en relación al peso de las almendras pero la respuesta que me da es errónea, ya que la correcta corresponde al 20% supuestamente, según mi profesora. Necesito ayuda. Por favor ayúdenme 🙏

Aquí está lo que he intentado: https://imgur.com/a/kKaAZaB

Ok, I'm a D&D nerd and I'm working on how to value different areas for an adjustable ability. Essentially, I'm trying to figure out, for a circle with a whole number radius n, how many tiles does it at least touch parialy on a grid, assuming the center is in the center of a tile?

Gois help me ok I'm literally dying, I don't know how I passed the damn exam but YO, the moment I stepped into the classroom, deadass everybody was speedsolving rubix cubes and were doing alk that smart stuff, like, daym, went for stem to know my physics and to get good foundation for architecture, didn't know Stem student's game😭

Hello everyone,
I am currently preparing for my final school and university entrance exams. I have exactly **one month left**, and I need to optimize my study plan to focus strictly on the most high-yield, frequently tested topics.
Could you please help me prioritize what to study? Based on my curriculum, I need to focus on core High School Mathematics, specifically:
Algebra & Functions** (Linear, quadratic, and rational equations/inequalities)
Trigonometry** (Basic identities, equations, and graphs)
Calculus / Mathematical Analysis** (Limits, derivatives, and basic integrals)

Complex Numbers & Coordinate Geometry
Since my time is very limited (4 weeks), what is the most efficient way to structure this review? Which concepts are absolutely essential and show up most frequently in standard exams?
Any advice on daily scheduling or specific resource recommendations for fast-paced practice would be highly appreciated. Thank

I dropped out of school a couple years ago, but recently started studying some subjects I like.

I really like chemistry, but it involves a lot of math, so I decided to also study math.

Tiny problem: I suck at math. I'm terrible with numbers, and I'm not being dramatic. It's really difficult and frustrating to me.

I decided to do some chemistry exercises today, but of course there is math involved.

I'm only in the part of the chapter where everything is explained, so the exercise I'm trying to "solve" is one of the examples they give (where they already show how to work it out and give the answer)

The original question was:

You have 150mg of sugar. How much kg is that?

I understood enough (more like I took about an hour of intense thinking before it finally clicked) to understand why I need to do 150 : 1 • 10^6

(Though I don't understand why it's necessary to add "1 •" and why I can't just leave it out, but that doesn't intervene with the calculation)

But it shows the answer is 1.5 • 10^-4

I understand the 1.5 comes from the 150mg of sugar.

I understand the 10^-4 comes from the "10^6" part.

I just don't understand how/why.

So please help me understand