Good morning sir,

In  general, there are five ways to decide the nature of a given square matrix based on the signs of the eigenvalues, for example

1. If the eigenvalues are positive then the nature is positive definite.
2. If the eigenvalues are negative then the nature is negative definite.
3. If the eigen values are nonnegative then the nature is Positive semidefinite.
4. If the eigenvalues are nonpositive then the nature is negative semi definite.
5. If the eigenvalues are positive and negative then the nature is indefinite.

triangle(T, [[x1,y1], [x2,y2], [x3,y3]]);

area:=proc(1/2*[x1(y2-y3)+x2(y3-y1)+x3(y1-y2)]);

AA:=(T)->[area(T)];

Hi, 

Struggling to get my head round how to plot the results of the follwoing, as it seems I have 4 variables...

I have a data file containing the results of the following problem:

1) Consider a cube. Each side (a,b,c) has a length of 1 unit.

2) Place an ion (0,0,0) where [a,b and c intersect] and find the associated energy at that point.

3) Move the ion to a point 0.05 units along side a to (0.05,0,0) and re-find the associated energy.

I want to solve the inequality sqrt(8*16^x - 1/2* 9^x) <= 3*4^x - 3^x

I tried 

restart:

solve(sqrt(8*16^x - 1/2* 9^x) <= 3*4^x - 3^x,x);

And I got 

Error, (in evala/inv/heuristic) cannot allocate memory (size=117506048).

How to solve the above inequality?

i do not want maple to round off some terms , for example 1.7777777777 which is rounded off 1.7777777778 . i do not want maple to round off the result,what should i do ?

Hi,

I'm trying to solve the following system of differential equations:

x''=(-c/m)*((x')^2+(y')^2)^1/2)*x'

y''=(-c/m)*((x')^2+(y')^2)^1/2)*y'

I need to solve them numerically as I've found out that trying to solve them analytically is impossible, and I really don't know how to do this in maple, I have initial conditions:

x(0)=0, y(0)=0, y'(0)=V0 sin theta, x'(0)= V0 cos theta.

Any help would be great.

Thanks

http://en.wikipedia.org/wiki/Twisted_cubic

1.

How to find S^3 : S^2*T : S*T^2 : T^3

2.

How to find X*Z-Y^2, Y*W-Z^2, X*W - Y*Z

Let a,b and c be the three roots of the equation :2012x^3+2013x+2014=0.Find (a+b)^3+(b+c)^3+(c+a)^3?

hello..

i have promblem, how i convert string to matrix and then, seprate row in matrix..

for example
a:=["0101101","0000101","0001001"]
 i want convert to matrix like..

Real application running a very long time in elimination step

z1 := Diff(x1(t),t) = x2(t);

z2 := Diff(x2(t),t) = x3(t);

z3 := Diff(x3(t),t) = x4(t);

z4 := Diff(x4(t),t) = -1*(1.0000*x4(t)-.5109*x3(t)-0.595e-1*x2(t)+3.1086*10^(-15)*(Diff(u(t), t, t, t))-(Diff(u(t), t, t))+.5109*(Diff(u(t), t))+0.595e-1*u(t));

with(Involutive):

with(OreModules):

Alg := DefineOreAlgebra(diff=[D,t], polynom=[t], comm=[a1,a2,a3,u]):

DD := evalm([[D, -1, 0, 0, 0],[0, D, -1, 0, 0],[0, 0, D, -1, 0],[0, -0.0595, -0.5109, D+1, (3.1086*10^(-15))*D^3-D^2+0.5109*D+0.0595]]);

DDtilde := Involution(DD,Alg);

ApplyMatrix(DDtilde, [lambda1(t),lambda2(t),lambda3(t),lambda4(t)],Alg)=evalm([[miu1(t)],[miu2(t)],[miu3(t)],[miu4(t)],[miu(t)]]);

E := Elimination(DDtilde, [lambda1,lambda2,lambda3,lambda4],[miu1,miu2,miu3,miu4,miu],Alg);

Hello..
 i have big problem, i dont know, how to add 0 in front.
firstly, i convert decimal to binary and  then i convert to string

but, how i add some 0 in front??
for exmple below..

list:=["1000","1","1110"]

i want to look like 7 bit
["0001000","0000001","0001110"]

i dont know how to count all digit, and how to add some 0 to front , and also have 7 bit?

okay so i have to write a maple function that decides wheter a line given by a vector that spans it intersects a triangle with given vertices. 

an example of what it should look it is 

ISC([[0,0],[10,10],[10,10]],[2,1]) returns true

ISC([[0,0],[10,10],[10,0]],[-2,1]) returns false

thanks in advance.  i'm just having severe problems with writing functions and what not as you can tell. anyway, Thanks!!

okay so the question i have to answer is "write a maple function that computes the area of a triangle in the plane from the coordinates of the vertices"  

ive gotten this far 

with(geometry);

triangle(ABC, [point(A, 0, 0), point(B, 2, 0), point(C, 1, 3)]);

area(ABC);    3

but how can i write so when you type say AA([[0,0],[10,10],[10,0]])  it returns  50?  (AA being the function name)

Thanks in advance to whoever helps.

I have asked this question before (2008) but no one answered. I just repeated my error and am still flummoxedflummoxed.

In early versions of Maple (Maple 1 Maple 3) one could halt a computation on the Mac by holding down the command key and the period; Maple would respond quickly. Now one can try that or click on the red hand in the tool bar and interrupt the computation but it doen not necessarily stop.

I inserted a print command in a procedure so that I culd...

Can anybody tell me what error is in the following function?

F:= ([[a,b], [c,d], [e,f]]) -> (1/2) abs((c-a)(f-b)-(e-a)(d-b));

Thank you!