From an exercise in "Game Physics", we have the following piecewise position vector r. We wish to show that it is well-defined (as well as twice differentiable) at 0. The goal of the exercise is then to show that the Normal vector is not even continuous. So we try:
```
p1,p2 := <t,t^3,0>, <t,0,t^3>;
r := piecewise( t<0, p1, p2);
limit(r,t=0,left);
```

and unfortunately that limit gives
RTABLE(149559852,MATRIX([[t], [t^3], [0]]),Vector[column])
as a result!
The obvious thing to try next is to "push in" the piecewise into the components. But the

Hi,
I have a small problem. I want to export code to Matlab. The code is mostly a long expression with some named constants. The constants are set to some values in Maple and in Maple only the x-variables are therefore unknown in the expression. However, in the exported code, some of the constants are not replaced by their values. Does someone have a clue what this depends on?
Best regards
Johan

Suppose the adjacency matrix M is given. How we can get the graph of it from Maple? Can we draw the graph now?
Thanx.

can I change the behavior of maple to not represent 1/sqrt(2) as sqrt(2)/2? I guess in a mathmatician's view this is a simplification, but not from an engineering standpoint.
also, if I perform combine(sqrt(2)/(sqrt(m)*sqrt(k)),radical,symbolic) I get sqrt(2)*sqrt(1/m k) instead of the desired sqrt(2/(k*m))..is this related?
I'm sure there is a nuance that I am not getting...

i am trying to plot a moving particle on two separate sphers of different radii. i have the code:
restart:
> with(plots):
> with(plottools):
> p1:=plot3d([3*sin(u)*cos(v),3*sin(u)*sin(v),3*cos(u)], u=0..Pi, v=0..2*Pi,color=red,
> style=wireframe,axes=normal,scaling=constrained):
> p2:=plot3d ([2.9*sin(u)*cos(v),2.9*sin(u)*sin(v),2.9*cos(u)], u=0..Pi, v=0..2*Pi,color=blue,axes=normal,scaling=constrained):
> p3:=display(p1,[seq( pointplot( { [3*sin(u)*cos(v)(k/50)(n/50),3*sin(u)*sin(v)(k/50)(n/50),3*cos(u)(k/50)(n/50)],[2.9*sin(u)*cos(v)(k/50)(n/50), 2.9*sin(u)*sin(v)(k/50)(n/50),2.9*cos(u)(k/50)(n/50) ] } ) , (k,n)=(0..314,0..314) ) ],insequence=true):

If i have a sequence of r[i+1] = 2r[i-1] + 3r[i] (where [i] represents subscript i) how do I use the 'do' function to go from the point where initially r[i-1] is, for example, 3 and r[i] is 4 to the point at which r[i-1] is first greater than 300 and find r[i+1] at this point.
I hope this question makes sense!
Thankyou

Have spent much of the weekend reading the maple help files and googling but still haven't found a current way to do this on XP with v9.5. Tried editing the maple9.5.ini file to point to the folder, but it doesn't work and seems to behave more like a log file. I can use libname as a line in the worksheet but would prefer to do without as I use the modules a lot.
Any suggestions would be welcome.
Neil

How do I plot f(x) in the following question?
f:=x->sum(h(2^n*x)/(2^n),n = 0 .. 20)
h(x)={ 2x , 0<><>

is there any way to do quantum field theory on maple 11 even if it means to have an add on package? answer will be helpful

How can I evaluate the eigenvectors of a 2x2 Matrix with trig functions as entries? This is what I did:
```
with(LinearAlgebra):
K:=<<cos(theta)|sin(theta)>,<sin(theta)|-cos(theta)>>;
Eigenvectors(K);
Error, (in LinearAlgebra:-LA_Main:-Eigenvectors) expecting either Matrices of rationals, rational functions, radical functions, algebraic numbers, or algebraic functions, or Matrices of complex(numeric) values
```

I'm wondering why cos(theta) shouldn't be an algebraic function ??
Assuming theta to be real I get the same.

In a

previous blog entry
I described a novel method, proposed by Robert Israel,
for sorting a list of lists of small positive integers,
specifically those less than 256.
It is significantly faster than the usual method.
Roman Pearce responded with a method for rapidly sorting listlists of integers
(a

*listlist* is a list of sublists with identical number of elements),
regardless of size.
While not as fast as Robert's technique,
it, too, is significantly faster than the usual method
and has no restriction on integer size.

How can I plot some velocity vectors on a circle. the function of velocity vectors is
(1+cos(t))i+(sin(t))j
thank you very much

So, why are we given two ways of defining a function, one using " := " and the other using " -> "? The latter seems pretty clunky. What use is it?

There is an icon in the Expressions pallete for "eval". Why isn't there one for "algsubs" which seems to be far more useful than the "eval" command.
Or maybe I've missed something.....

I would like to animate a function and its derivative together in a sort of trace feature like you can do on a TI calculator. I am unsure if this is even possible, was wondering if someone else has done it or has any ideas...
Thanks in advance,
Brandon