# Learn Math

##### Plot The volume of a cylinder between a cone and XY
I want to plot the volume of a cylinder between a cone and the plane XY The equation of the cone is zz == √x2+y2\sqrt{x^2...
##### Interpreting P-Value on ParameterTable
When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property “ParameterTable”. Looking in the documentation...
##### Manipulating List?
I have a huge list with 1000 elements. Manually entering and calculating SUM of probabilities it would take a few hours. Example: list = {1,...
##### PlotLegends in ListPlot does not display different markers
I would like to plot a graph with the legends at its side. However, I have managed to plot the legends, but the markers do...
##### FindMinimum function does not produce minimum from near point
Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. H1 = {{1, 2}, {3, 4}};...
##### Table of ParametricPlots crashes Kernel
I can usually crash the Mathematica Kernel by using Table to generate a List of ParametricPlots, as follows: testpara[α_] := ParametricPlot[ { {Cos[θ], Sin[θ]}, {2...
##### Plot The volume of a cylinder between a cone and XY
I want to plot the volume of a cylinder between a cone and the plane XY The equation of the cone is zz == √x2+y2\sqrt{x^2...
##### Interpreting P-Value on ParameterTable
When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property “ParameterTable”. Looking in the documentation...
##### Manipulating List?
I have a huge list with 1000 elements. Manually entering and calculating SUM of probabilities it would take a few hours. Example: list = {1,...
##### PlotLegends in ListPlot does not display different markers
I would like to plot a graph with the legends at its side. However, I have managed to plot the legends, but the markers do...
##### FindMinimum function does not produce minimum from near point
Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. H1 = {{1, 2}, {3, 4}};...
##### Table of ParametricPlots crashes Kernel
I can usually crash the Mathematica Kernel by using Table to generate a List of ParametricPlots, as follows: testpara[α_] := ParametricPlot[ { {Cos[θ], Sin[θ]}, {2...
##### Animation of a plane wave
I want to animate in 3D the plane wave sin(ωt+kx+ϕ)sin(ωt+kx+ϕ)\sin(\omega t+kx+\phi), but following the form from the documentation, I can only make kkk or ωω\omega...
##### Removing solutions which are particular cases of others
I have an algorithm which gives me a list of solutions (in matrix form, if it is of any importance) of an equation. Some of...

## Does Pi contain all possible number combinations?

I came across the following image, which states: π\pi Pi Pi is an infinite, nonrepeating (sic) decimal – meaning that every possible number combination exists somewhere in pi. Converted into ASCII text, somewhere in that infinite string if digits is the name of every person you will ever love, the …

## Mathematical difference between white and black notes in a piano

The division of the chromatic scale in 77 natural notes (white keys in a piano) and 55 accidental ones (black) seems a bit arbitrary to me. Apparently, adjacent notes in a piano (including white or black) are always separated by a semitone. Why the distinction, then? Why not just have …

## Why can you turn clothing right-side-out?

My nephew was folding laundry, and turning the occasional shirt right-side-out. I showed him a “trick” where I turned it right-side-out by pulling the whole thing through a sleeve instead of the bottom or collar of the shirt. He thought it was really cool (kids are easily amused, and so …

## Splitting a sandwich and not feeling deceived

This is a problem that has haunted me for more than a decade. Not all the time – but from time to time, and always on windy or rainy days, it suddenly reappears in my mind, stares at me for half an hour to an hour, and then just grins …

## How to study math to really understand it and have a healthy lifestyle with free time? [closed]

Here’s my problem. I’m studying math and when I really work hard, I think I understand things very good, but that comes at a big cost: in the last few years, I’ve had practically zero physical exercise, I’ve gained 30 kg, I’ve spent countless hours studying at night, constantly had sleep …

## 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 mathematically beautiful at the same time. Do you know of any other concepts like these? ================= …

## Is dydx\frac{\textrm{d}y}{\textrm{d}x} not a ratio?

In the book Thomas’s Calculus (11th edition) it is mentioned (Section 3.8 pg 225) that the derivative dydx\frac{\textrm{d}y}{\textrm{d}x} is not a ratio. Couldn’t it be interpreted as a ratio, because according to the formula dy=f′(x)dx\textrm{d}y = f'(x)\textrm{d}x we are able to plug in values for dx\textrm{d}x and calculate a dy\textrm{d}y …

## How long will it take Marie to saw another board into 3 pieces?

So this is supposed to be really simple, and it’s taken from the following picture: Text-only: It took Marie 1010 minutes to saw a board into 22 pieces. If she works just as fast, how long will it take for her to saw another board into 33 pieces? I don’t …

## What was the first bit of mathematics that made you realize that math is beautiful? (For children’s book)

I’m a children’s book writer and illustrator, and I want to to create a book for young readers that exposes the beauty of mathematics. I recently read Paul Lockhart’s essay “The Mathematician’s Lament,” and found that I, too, lament the uninspiring quality of my elementary math education. I want to …

## Can I use my powers for good? [closed]

================= ================= 29 Answers 29 ================= If you are in the US, there are several thousand institutions of higher learning, and at many of them there is very little “pressure to publish”. At others, the “pressure to publish” can be met by publishing a textbook or some work of scholarship …