It is known that the trigonometric functions of an integer number of degrees may be expressed by radicals if the number of degrees is divisible by 3. Simple code finds all these values ​​in the range 0 to 90 degrees:

 [sin(`0`^`o`)=0,`   cos`(`0`^`o`)=1,`   tan`(`0`^`o`)=0,`   cot`(`0`^`o`)=infinity];

for n from 3 to 87 by 3 do

[sin(n^`o`)=convert(sin(n*Pi/180),radical...

Dear friends,

this is to share with you what a joy it was to work with Maple on the problem of enumerating non-isomorphic graphs. This problem goes back to Polya and Harary and it is a beautiful example of Polya counting, while also being of notable simplicity, so that a high school student or an undergraduate can follow it easily.

I have worked on this problem over the years, adapting my solutions in Cocoa and Lisp as I gained insights. My first attempt used...

Here is a plot in table format of the standard Times, Helvetica, and SYMBOL fonts. This plot provides a reference table that can be used to find the character codes to plot any one-byte character that can be plotted, which is especially useful for the SYMBOL characters and character codes 128-255 in the standard fonts. These characters are available for plotting in both the Standard and Classic GUIs.

All characters are aligned to be immediately above and immediately...

The Maple dsolver is very powerful, but everything has advantages and disadvantages. I was recently asked the following question.
Let us consider the system of ODEs
>restart; sys := [diff(y(x), x) = -(4*cos(x)*y(x)+z(x)*cos(x)^2+3*z(x))/(sin(x)*(cos(x)^2-9)),
>diff(z(x), x) = -(y(x)*cos(x)^2+3*y(x)+4*z(x)*cos(x))/(sin(x)*(cos(x)^2-9))]:
The functions
>y1 := C[1]*(cos(x)+1)^(1/2)/(cos(x)+3)^(1/2)+C[2]*(1-cos(x))^(1/2)/(3-cos(x))^(1/2):
>z1 := -C[1...

Clock:=proc(H, M)  # H and M - time in hours (0 <= H <= 23) and minutes (0<=M<60)

local A1,A2, A, B, B1, C1, C, E, F,alpha,t, T, T1, T2, P, G;

uses plottools, plots; 

A1:=(irem(H,12)+M/60)*30;  A2:=M*6;

A:=circle([0,0], thickness=5);

P:=disk([0,0], 1, color=grey);

Throughout evolution, natural selection is one source of genetic change in populations. However it is possible for a mutation to become common in a population entirely by accident through a phenomenon known as genetic drift. 

It works most strongly in small populations or dramatically fluctuating populations.  When non-lethal mutations occurs it is possible not just because of adaptation but by chance it will have more offspring than it's neighbors. 

Here are two procedures associated with a clock with hands. I think they are interesting not only for fun, but will be useful for teachers in schools in the preparation of such tasks.

The first procedure called  ClockHandsAngle  finds the angle between the hands of the clock at any time.

The second procedure called  TimeFromAngle , for a given angle finds all times in a given time range. The first procedure  is...

    A powerful approach to the teaching and learning of mathematics for students of science and engineering has been made practical through the development of powerful general mathematical software, of which Maple provides the least steep learning curve.  Accordingly, it is timely to produce an interactive electronic textbook that, for students of chemistry -- also biochemistry and chemical engineering, has as its objective in part I,
Mathematics for...

Fridays Killer Questions 7city Learning:

Question) The number sequence is: 2 1 3 6 5 11 18 17 which number should come after 17?
Answer) 35

Fridays Killer Questions 7city Learning:

Question) You're the captain of a pirate ship and your crew gets to vote on how the gold is divided up. If fewer than half of the pirates agree with you, you die. How do you recommend apportioning the gold in such a way that you get a good share of the booty, but still survive?

Answer) You divide the booty evenly between the top 51% of the crew.

Fridays Killer Questions 7city Learning:

Question) Calculate the number of degrees between the hour hand and the minute hand of a clock (non digital) that reads 3:15.

Answer) The minute hand will be horizontal and the hour hand will also almost be horizontal but it will have moved ¼ of an hour 12 hours=360 degrees, 6 hours = 180 degrees, 3 hours =90 degrees, 1 hour = 30 degrees, ¼ of an hour=7.5 degrees

Fridays Killer Questions 7city Learning:

Question) You have two containers, one holds five gallons, the other holds three. You can have as much water as you want. Measure exactly four gallons of water into the five gallon container.

Answer) Fill up the three-gallon container and pour it into the five-gallon container. Do it again – there will be one gallon left in the three-gallon container. Empty the five, pour in the one,...

Fridays Killer Questions 7city Learning:

Question) You have 100 kg of berries. 99% of the weight of berries is water. Time passes and some amount of water evaporates, so our berries are now 98% water. What is the weight of berries now?

Answer) The unexpected, yet correct, answer is 50 kg. It seems like a tiny amount of water has evaporated so how can the weight have changed that much? There is clearly 1 kg of solid matter in the...

Consider two sets in the Euclidean plane, each consisting of 4 points.

First set:  A(0, 0),  B(3, 4),  C(12, 4),  E(4, -1)

Second set:  F(0, -8),  G(12, -4),  H(9, -8),  K(4, -9)

It is easy to check that the set of all pairwise distances between the points of each of the given sets (6 numbers for each set ) are the same. At the same time it is obvious that there is no any...

Fridays Killer Questions 7city Learning:

Question) There are eight balls, one of which is slightly heavier than the others. You have a two-armed scale, which you are allowed to use only twice. Find the ball that’s heavier.

Answer) Put three balls on each side of the scale. If the arms are equal, you know the heavy ball is one of the two remaining. If the arms are unequal, take the three balls on the heavier side, pick two and weigh them against each other.