I'm seeking advice on the best way to get past Maple's (Vr4 for OS/2)
refusal to compute numerically a double integral over a rectangular area.
The integrand has a crease in one corner, but otherwise is well behaved.
By crease I mean that as that corner is approached the function value
depends (as cos(phi)) on the direction of approach, but is finite.

Even when I exclude that corner from the area of integration (by some
distance r0), and ask only for low accuracy (5 or 6 digits), after several
minutes cogitation Maple announces

Error, (in evalf/int) function does not evaluate to numeric

In fact, evaluation of the integrand anywhere in the are of integration
produces perfectly sensible numbers, so I don't understand what problem
Maple is encountering. The problem persists when I add to 'Int' any of
the flags _CCquad, _Dexp, and _NCrule. Here's the integral (the first 4
lines are just to show the integral more clearly):

Can we write a program which will eventually display ALL possible chess games?

Yes, you heard right. ALL possible chess games. You don't think so? Think again.

Here's a short analysis with a Maple worksheet which does exactly that:

http://ioannis.virtualcomposer2000.com/math/EveryChess.html

My appreciation and many thanks to Johan E. Mebius who sent a reference with the
idea.

The polynomial like f:=x^m+x+1, and m is symbol.
I would like to get the vector consist of its coefficients.
Such as a vector with m+1 dimensions.
Thanks.

Hello,

Maple 12> s:= arctan(3 + sqrt(8) + sqrt(14 + sqrt(200))) +
Maple 12> arccot(1 + sqrt(2) + sqrt(4 + sqrt(32)))/2:

Maple 12> simplify(simplify(s));

Error, (in simplify/constant) numeric exception: division by zero

QED
?

Best wishes,

Vladimir Bondarenko

VM and GEMM architect
Co-founder, CEO, Mathematical Director

http://www.cybertester.com/ Cyber Tester, LLC
http://maple.bug-list.org/ Maple Bugs Encyclopaedia
http://www.CAS-testing.org/ CAS Testing

Hello,

int(arctan(z^(1-I))/(z^2 + 1), z= 0..infinity);

?

Cheers,

Vladimir Bondarenko

VM and GEMM architect
Co-founder, CEO, Mathematical Director

http://www.cybertester.com/ Cyber Tester, LLC
http://maple.bug-list.org/ Maple Bugs Encyclopaedia
http://www.CAS-testing.org/ CAS Testing

Hello,

I'm using Maple 11 on Mac OS and I have experienced some weird
calculations with Maple. Since my experience with Maple is rather
limited I wouldn't go as far as calling it a bug rather put for
discussion here. Additionally English is not my native language,
therefore some mathematic expression I use may appear odd.

http://xgm.de/RT/RT.mw.html
This is the HTML export, nothing altered. The Maple worksheet:
http://xgm.de/RT/RT.mw

The polynom (1) has the zero points 0 and -50 as (2) says. Therefore
it can also be composed with the linear factors (s-0)*(s+50). Same
applies to (3).

(1): s^2 + 50 s = (s-0) * (s+50)
(3): s^2 + 20 s + 100 = (s+10)*(s+10)

In (5) I define P composed from the two original terms and in (6) L
composed of linear factors.

L and P should be equal since its numerator and denominator are equal.
But Maple tells me they are not equal.

Can anyone tell me what's wrong here?

Please look at commands below:

with(Physics[Vectors]):
k_:=kx*_i+ky*_j+kz*_k:
r_:=x*_i+y*_j+z*_k:
Nabla(k_.r_);

kx*_i+ky*_j+kz*_k

In fact the answer is vector k_, but the result isn't the traditional
form. How can I let Maple give the answer just as k_ not its expansion?

Hello,

int(sqrt(sqrt(z^4+1)+z^2)/((z+1)^2*sqrt(z^4+1)), z=0..infinity);

?

Cheers,

Vladimir Bondarenko

VM and GEMM architect
Co-founder, CEO, Mathematical Director

http://www.cybertester.com/ Cyber Tester, LLC
http://maple.bug-list.org/ Maple Bugs Encyclopaedia
http://www.CAS-testing.org/ CAS Testing

Hello group,

I'm trying to solve a simple differential equation using maple. Its
about an object flying in air with friction. At time 0 it's propelled
with 330 m/s and its falling down (i.e. someone shoots a bullet out of a
plane right downwards).

cw := 0.5; # Widerstandsbeiwert
rho := 1.293; # kg / m^3
A := 0.003^2; # Stirnfläche in m^2
k := 0.5 * cw * A * rho; # kg / m
g := 9.82; # m / s^2
mass := 0.001; # kg

Then the equation:

dgl := mass * diff(v(t), t) + k * v(t)^2 = mass * g;

And the solution:

V := rhs(dsolve({dgl, v(0) = 330}, v(t)));

Checking values now works quite well:

-6
330.0000003 + 0.3725299084 10 I

In Maple 12, when I input a command such as
Sum(Pi/k^2, k = 1 .. 10);
Maple will give a 2D output, and I can change its font style from
tools bar. However, the Greek symbols will not change as the English
characters.
Why does this happen and how to change it?