Questions related to the teaching and learning of mathematics.

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8
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1answer
142 views

why is that most of the books in mathematics don't include answers?

I am currently going through the " Topics in Algebra" By I. N. Herstein. The problems are pretty good. But there are no answers on the back. Same is the case with "Mathematical Analysis" by Rudin. I ...
0
votes
2answers
31 views

Power calculation for simplification?

I have this simple question I saw here: ±(2 - 2^(-23)) × 2^128 = ±6.8 × 10^38 How did they get to ...
0
votes
1answer
109 views

Parabola problem. How far from the vertex is the focus?

A spotlight has a parabolic cross section that is 8 ft wide at the opening and 2.5 ft deep at the vertex. How far from the vertex is the focus? I'm getting 8/5 ft. Is this correct? Appreciated!
5
votes
2answers
140 views

Why the $\log$ is so special?

When I first learn about the logarithm function $\log$ or $\ln$. My professor said that $\log x$ is a function that when we derive we get the inverse function $1/x$. This $\log$ becomes very popular ...
5
votes
1answer
125 views

Is an undergraduate in engineering sufficient preparation for a masters in mathematics?

I'm a high school student who is considering doing an undergraduate in engineering. However my the long term plan is to pursue math at a higher level. I want to do engineering at undergrad because I ...
1
vote
1answer
69 views

Max value - Mantissa calculation clarification?

I've been reading this article about floating point representation floating point representation is : Where mantissa is : All understood. But they also say : How did they get to ...
84
votes
20answers
15k views

Visually deceptive “proofs” which are mathematically wrong

Related: Visually stunning math concepts which are easy to explain Beside the wonderful examples above, there should also be counterexamples, where visually intuitive demonstrations are actually ...
-2
votes
1answer
32 views

Null Hypothesis and Confidence Intervals

I was told that If I reject the null hypothesis than my CI will not include the population mean. However the problem that I just did has a population mean of 2.72 and a lower CI of 2.5 and an upper CI ...
0
votes
1answer
481 views

Upper and Lower Bounds for Confidence Intervals on a one tail hypothesis test.

CI(99) = xbar ± Zcv( σ / √ n -1 ) My question is if the test is a one tail hypothesis test, do I still do two separate equations + and -. Here is the formula filled in (if it is the correct ...
0
votes
1answer
13 views

Why am I getting 84.25 instead of 97.68 for my Confidence Interval?

Why am I getting 84.25. I am doing 97.96*(6/sqrt[50-1]) = 97.96*(6/7) I am obviously not doing this correctly please help. It has been sometime since I have done any math.
9
votes
6answers
1k views

Should I do all the exercises in a textbook?

The problem sets that you usually get in a university course is a small fraction of the exercises in your textbook. Which raises a question: do you need to solve all the exercises from your textbook? ...
0
votes
0answers
56 views

Move Hill equation curve horizontally without changing its shape?

I have a normal Hill function of: $y = \dfrac{x^\lambda}{h^\lambda + x^\lambda}$; where $\lambda$ is Hill coefficient, and $h$ indicates the infection point. I am concerning if we could add another ...
2
votes
1answer
45 views

Looking for mathematics teaching article

Some time in the last month, I read a great article somewhere on the web that discussed the sorry state of secondary school math education in the U.S. One of the examples in that article was a ...
1
vote
1answer
37 views

Can I use order of operations (BIDMAS) on any question?

Does BIDMAS only apply to simple calculations, or can you use them in algebra etc?
0
votes
1answer
23 views

return a number between 3 to 5 by get a number between 1 until 10000! [closed]

I want to have a math math formulas to do this operation: A:get a number between 1 to 10000 B:reteun a number between 3.00 until 5 for example 3.89 for greater number return greater number too! ...
4
votes
2answers
123 views

I'm stuck with rounding decimals and have been for years

I'm in year 10 and have a B grade - yet still manage to mess it up when I face a question regarding decimals. For example: Round 8.647 to one decimal place. Would this be 8.7 or 8.6 as I have never ...
0
votes
1answer
182 views

A Ferris Wheel Word Problem (Trigonometry)

Please help, will give me an idea how to do more of these. A Ferris Wheel called Colossus has a diameter of 158 feet. Using the figure as a model, find the distance traveled by someone starting at ...
3
votes
2answers
2k views

Linear Homogeneous Recurrence Relations and Inhomogenous Recurrence Relations

I'm having some difficulty understanding 'Linear Homogeneous Recurrence Relations' and 'Inhomogeneous Recurrence Relations', the notes that we've been given in our discrete mathematics class seem to ...
511
votes
46answers
312k views

Visually stunning math concepts which are easy to explain

Since I'm not that good at (as I like to call it) 'die-hard-mathematics', I've always liked concepts like the golden ratio or the dragon curve, which are easy to understand and explain, but are ...
0
votes
0answers
38 views

Finding an exam grade average

Someone else got a 68% on their first account and an 83% on their second account. At a minimum, what value do they need on the third account so that their overall bank dividenda (mean) is at least an ...
10
votes
4answers
836 views

Why would you expand a square wave in a Fourier series?

The periodic square wave $$ f(x) = \cases{ 1 \text{ if } 0 \le x \le \pi \\ 0 \text { if } -\pi \le x < 0} $$ seems easy enough to work with. Why transform it into a series of sines and cosines? ...
1
vote
0answers
60 views

Necessity of writing Math in a patent?

I don't know if its appropriate question here...but I anyway want to try... I have an algorithm in which I have a finite data in which each element is assumed as an element of a metric space with a ...
2
votes
0answers
46 views

Pen-and-paper educational games

I'm teaching maths at the 8-16 year level, one-on-one tuition. What are some good pen-and-paper maths games I can play with these kids? Googling "math games" just gets me a load of interactive ...
0
votes
1answer
26 views

What are the variables by which I can differentiate the different fields of math?

Ironically, I'm on a mathematics-based forum using the terms "variables" and "differentiate" in entirely non-mathematical ways, but what I mean by this question is as follows: I'm self-studying and ...
3
votes
2answers
75 views

Help finishing proof via induction for a summation

So I have to prove the following equation using induction for n >= 2: $$ \sum\limits_{i=1}^n 4/5^i < 1 $$ However the question asks me to prove something stronger such as this: $$ ...
4
votes
3answers
444 views

Solve the equation $(x-3)(x+9)(x+5)(x-7)=385$

I have one question please...I solved it in this way..so I am not sure..that is it right or not? and If I solved it in the wrong way..so would like to know about the correct way and method to solve ...
0
votes
1answer
62 views

$S=\{0,1,2,3\}$. Show that $(S,+)$ is a Semi group where $+$ defines addition Modulo 4

I have search out my whole maths book for it..but didn't got this question in my book and I need to learn it for my exam..So if you people can please solve this for me? $S=\{0,1,2,3\}$. Show that ...
3
votes
1answer
181 views

Bessel function integral

How to solve the integral for $J_1{(2x\sin{\frac{\theta}{2}})}$ at $[0,\pi]$? If solving by Matlab, please provide me the source. Thank you!
3
votes
3answers
461 views

Is it possible to learn abstract algebra no precalculus or calculus?

See above. I am trying to re-teach myself mathematics in a different manner than is formally taught (i.e., set theory, number theory, mathematical logic, abstract algebra, discrete math and then ...
0
votes
0answers
61 views

Comic that makes clear that it might be a good idea to prove something…

I want to make a teaching unit in a high school class about beautyfull elementary mathematical proofs. At the beginning I want to motivate that it is really essential to proof something (because ...
1
vote
0answers
28 views

Strange conundrum involving mean and variance of numbers.

Given $n$ numbers $a_1<a_2<...<a_n$ how would we find a $m$-element subset ($m \leq n$), with the smallest variance? If I knew what the optimal mean for the smallest variance is I could just ...
1
vote
3answers
163 views

Set Theory, Number Theory, and Logic before any other math

I am trying to teach myself set theory, number theory and logic before I engage in mathematics. I have been able to get through Calculus but I think that it was just by repeating different types of ...
0
votes
0answers
140 views

Don't feel like I grasp the mathematics I'm supposed to understand

In high school, I used to spend my free time proving the formulas that we were asked to use. I'd prove loads of formulas in Calculus that we never even studied, just because I enjoyed getting to the ...
0
votes
0answers
37 views

Learning resources for Probability Distributions/Models

I've a good background in basic probability. I need to learn and get a good grip on the probability distributions and stochastic processes, counting processes, and other related topics. I am already ...
3
votes
5answers
123 views

Chain Rule: Is the notation $\frac{dy}{du} \cdot \frac{du}{dx} = \frac{dy}{dx}$ accurate?

My question is if it is okay / mathematically rigorous to write the Chain Rule like that (the Leibniz way). I thought that $dx$, etc. do not follow the rules of algebra and cannot be treated as such. ...
4
votes
3answers
248 views

University-level books focusing on intuition?

I help some students with difficulties in Mathematics and Physics (especially math, physics, and engineering majors). While in high school they usually don't study, or are not interested, etc., in ...
14
votes
6answers
3k views

Why teach linear algebra before abstract algebra?

Is there a reason why most undergraduate curriculums put linear algebra before abstract algebra? I'm asking this because personally it seems to be much easier to understand the architecture behind ...
0
votes
2answers
97 views

linear congruence questions

A: For the two systems of linear congruences, one system has integer solutions while the other does not. For the system with integer solutions, write down 2 of them whose difference is less than 192. ...
16
votes
11answers
973 views

Why limits work

I'm currently a first year student in electrical engineering and computer science. I know how to compute limits, derivatives, integrals with respect to one variable that is things from one variable ...
0
votes
1answer
61 views

Calculating $\lim\limits_{x \to 0} \frac{10^x - 2^x - 5^x + 1}{x \cdot \tan x}$ [duplicate]

I am trying to solve this limit without using Taylor expansions to explain it to a secondary school student $$\lim_{x \to 0} \frac{10^x - 2^x - 5^x + 1}{x \cdot \tan x}.$$
2
votes
2answers
123 views

$f(x)=\sin(43x)+\cos(2x)$ is periodic function?

$f(x)=\sin(43x)+\cos(2x)$ is periodic function. I got the period of $\sin(43x)$ is $\frac{2\pi/}{43}$ and period of $\cos(2x)$ is $\pi$. Then the period of $f(x)$ is $2\pi$. Am I right? Any comment? ...
0
votes
0answers
20 views

Does Volterra’s example prompted development of a generalization of the Riemann integral?

Volterra's function is a real-valued function X defined on the real line R with the following curious combination of properties:(a)X is differentiable everywhere. (b)The derivative x ′ is bounded ...
2
votes
1answer
1k views

Real world applications of exponential function; continous case

I am looking for interesting applications in everyday life, technology or science of exponential functions of the type: $$ f\colon \mathbb{R} \to \mathbb{R}, \quad x \mapsto ab^x $$ for the case $a ...
0
votes
1answer
25 views

How to work out 3 dimensional vector angles

I've come across this question and cant for the life of me think how to work it out. I understand working out the angle between two vectors e.g. given, vector a(2i+3j-k) and vector b(8i-6j+2k) but am ...
2
votes
1answer
132 views

About the epsilon definition of a convergent sequence. Is this definition equivalent?

I read that it is appreciated to include the context and motivation of a question. I may have overdone this a little bit in this question. To summarize, my question is: Are the two blockquoted ...
64
votes
14answers
6k views

Should an undergrad accept that some things don't make sense, or study the foundation of mathematics to resolve this?

I'm a second year math student. And I've the following problem. When I prepare myself for an exam, I can distinguish two phases. First I'm mainly interested in whatever is necessary to pass the ...
0
votes
1answer
221 views

I want to pursue Computer Science as a major but I don't know if i should…HELP!? [closed]

I'm currently a second semester sophomore who's currently pursuing a Global Affairs major and minoring in Japanese Studies. I plan on going to law school after college and I'm interested in ...
0
votes
1answer
47 views

Pre requisites of linear algebra

I want to learn abstract linear algebra. Do I require the knowledge of discrete mathematics before I start? I have the impression that abstract maths and their proofs can be understood easily by the ...
5
votes
1answer
309 views

When should I start learning Set Theory?

I started to learn a few disciplines on my own over the break after my first year in college and one of them was Real Analysis. In the process I came across many issues in Analysis texts concerning ...
2
votes
1answer
95 views

Elementary “bugs” in computer algebra systems?

There's a discussion of bugs in CAS's here, but these are technical errors of interest mainly to the professional mathematician. I am more interested in simple errors which might arise in the use of ...