This is my question that I posted at http://mathematica.stackexchange.com/questions/32338/is-there-a-triangle-like-this "I want to find the numbers $a$, $b$, $c$, $d$ of the function $y = \dfrac{a x + b}{c x + d}$ so that the triangle $ABC$ with three points  $A$, $B$, $C$  have integer coordinates and lies on the graph of the given function, then the centroid of the triangle $ABC$ (have also integer coordinates) is also lies on the graph". The ansewr at that site...

How can version 17 be forced to produce [VectorCalculus]TangentLine results consistent with previous versions?

Suppose you have a 3D position vector defining a curve using a parameter t.  One can evaluate the curve at a specific value of t.  Say the point is p.  One can differentiate the curve and evaluate it at the specified value of t.  Say the result is the vector v.  Then the tangent line is p + tv.  The VectorCalculus Tangent Line...

Hello,

In multibodies system, there exists many kind of coordinates namely joint (or relative) coordinates and absolute coordinates. Moreover, for the joint (or relative) coordinates, it is possible to choose strict, simplified, or complete coordinates.

For the moment, i only find in the tutorials system modeled with complete joint (or relative) coordinates. I will give the example of a 4 bars mechanism. The kinematic scheme with this complete joint coordinates is the following :

@Carl Love  Thanks for your reply. Composition breaks down into  distinct ordered  k-tuples . Partition breaks down into all possible sums with no regard to order.

Example: composition (4, 2)    {[1,3], [2,2], [3, 1]}   allstructs (Partition (4) ,size = 2)     [ [1, 3], [2,2]] 

For the allstructs ( Partition (n...

Find all prime numbers from 500 to 600.

Good afternoon

I request you to help me out to input a column vector matrix of dimension 80x1 whose entries are 0.

would like to use point graph and line graph to show the graph

restart;

test1r3 := (1/2)*(-x+sqrt(x^2-4*y^2))/y;

n := 100;

for j from 1 to n do

aa[j] := subs(y=RandomTools[Generate](integer(range = 1 .. 10)),subs(x=RandomTools[Generate](integer(range = 1 .. 10)),test1r3));

od;

plot(<seq(1 .. n)>,<seq(aa[i], i = 1 .. n)>, style = point);

How do i "show region ranges" on mac. on windows you just press F9 but you cant on mac??

Find

A travel agency is planning a one-week trip to Italy that has an initial cost of $2,000 plus $1,140 per person. At a price of $1,400, 13 people will sign up. Past experience suggests that for each $20 decrease in the price, an additional person will sign up. Also, for each $20 increase in the price, one less person will sign up. What price (in intervals of $20) will maximize the profit? (Make a table and guess and check.)

I don't get how to solve this problem...

Find

In a pocket, we have balls number from to

Hello all,

I want to plot shapes, like circles, lines or elipses, and to shade some areas, for example, let's say I have an inequality, indicating a domain of all points above a line, or inside a circle, outside an elipse, and I want, for demonstaration for studetns, to shade with dashed lines or color these areas, how do I do that ?

Thanks !

I am using the ExportMatrix command to save matrices to .txt files. Is there a way to use a variable to automatically create the text file name?

For example (I know this doesn't work):

In maple 17, 

solve({b-a*sqrt(1+a^2+b^2)=a^2*(a*b-sqrt(1+a^2+b^2)), a-b*sqrt(1+a^2+b^2)=b^2*(a*b-sqrt(1+a^2+b^2))});

outputs

a=a , b = -a/(1+a)

If you set a =1  and b = -1/2 you will see this is not a correct solution.