Hi. I'm using the interactive plot builder. I click in add button in the expression section and then enter:

2x+y+2x-15=0

and click the accept button and I get an error message saying "Please enter a valid Maple expression". How am I supposed to enter the equation of the plane?

Thanks in advance!

1. The member() function doesn't find the value in a table if that value is associated with the key (aka index)  '0'
2. Doesn't seem to matter if the table is created explicitly (ie by calling table()) or implicitly (ie by simple indexed assignment)
3. member() doesn't seem to have the same issue with a zero-based Array()
4. I'm pretty sure that this is a bug, but I'd like some opinions before I report it
5. This behaviour has been around for a while: same thing happens all the way back to Maple 18. (I can't check anything earlier)

Check the ouput of member(10,t1) in the attached

Download memberProp.mw

This is a solution to a PDE. I solved this by hand and got a much simpler solution. Maple solution is also correct but very complicated. They are both the same, as when I plot them  for different t values, they match. I am sure they are the same. 

How would one simplify Maple solution to the simpler one? Tried number of options to simplify, but can't get Maple to simplify it to the hand solution. Also tried different assumptions on t and x (real, positive etc..) nothing helps.

Maple 2019.1 on windows 10. Physics 436

Download how_to_simplify.mw

hi

can anyone help me with this error.

why maple2019 gives result of trigonometric function in terms of I.

snapshot attached

I have an arc length parametrization question. The problem says to find a function g(s) that you can use to calculate the arc length parametrization, then find a formula for the arc length parametrization. I have r(t)= <cos(2t), sin(3t), 4t>. How would I do this?

I have a question about animating 3d space curves (vector-valued functions). I have a curve that has a component x(t), component y(t), component z(t), and a time, t. The problem says to create an animation of a point moving around the curve. How do I do this?

Thank you.

first I define some constants (note I may change the constants later based on the context of the application)

p_l := 10^(-15);     
epsilon := 1.09*10^(-10);
p_B := 1.09*10^(-8);

n_A := 10^7;         
k_A := 0;
n_B := 10^8; 
k_B := 0;

then I define a function l(x,y):

l := (x, y) -> x^k_A*(1 - x)^(n_A - k_A)*y^k_B*(1 - y)^(n_B - k_B)

Now I use both with(GlobalOptimization) and with(Optimization) to maximize l(x,y) give some constraints and I get:

GlobalSolve(l(x_1, y_1), x_1 = p_l .. epsilon, y_1 = p_B .. 1, maximize, initialpoint = [x_1 = 0, y_1 = 0]);
  [-0., [x_1 = 1.09000000000000 10^(-10)   , y_1 = 0.633548870211381]]

Maximize(l(x_1, y_1), x_1 = p_l .. epsilon, y_1 = p_B .. 1, initialpoint = [x_1 = 0, y_1 = 0]);
 [0.33621648834727435318,  [x_1 = 1.00000000000000 10^(-15)   , y_1 = 1.0900000000000000000 10^(-8)  ] ]

Clearly the second answer is right and the first is wrong... I am not sure why the ``global optimazation'' is doing worse than the normal and free ``optimazation''.. Am I using the GlobalSolve in a wrong way??

Hello people in mapleprimes,
I have a question.

I use maple2019 with mac os 10.14.6.

$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.14.6
BuildVersion:	18G95

With maple2019, errors appears.

> kernelopts(version);
        Maple 2019.1, APPLE UNIVERSAL OSX, Jun 6 2019, Build ID 1403154

> assume(a>-1,b>0);
> additionally(a<=1);
> about(a);
Originally a, renamed a~:
  is assumed to be: FAIL

> assume(tau<1,tau>0,s<1,s>0):
> a_e1:=tau*s*(1+tau)<tau*s+tau+s-1:
> b_e2:=expand(lhs(a_e1)-rhs(a_e1))<0:
>  b_e3:=collect(b_e2,s,factor):
> solve(b_e2,s) assuming tau<1;
Error, (in assuming) when calling 'property/ConvertProperty'. Received: 'FAIL
is an invalid property'

On the other hand, with maple2018, they do not.

> kernelopts(version);
       Maple 2018.2, APPLE UNIVERSAL OSX, Nov 16 2018, Build ID 1362973

> assume(a>-1,b>0);
> additionally(a<=1);
> about(a);
Originally a, renamed a~:
  is assumed to be: RealRange(Open(-1),1)

> assume(tau<1,tau>0,s<1,s>0):
> a_e1:=tau*s*(1+tau)<tau*s+tau+s-1:
> b_e2:=expand(lhs(a_e1)-rhs(a_e1))<0:
> b_e3:=collect(b_e2,s,factor):
> solve(b_e2,s) assuming tau<1;
                                    1
                               [{-------- < s~}]
                                 1 + tau~

Are errors due to some bugs in maple2019 when being used with mac os 10.14.6?

Take care.

taro

Is there or will there be a german version or is there a language pack available somewhere?

r=a+b sin(x), this is the function I want to plot the graph in polar co-ordinates but how to manage those arbitrary constants "a and b" ?

Hi everyone, I need someone’s expertise with the Maple Soft Application, I am currently into my 4^th day of my Maple Soft experience and also returning to School after many years. Can someone help me with the following codes to solve step by step Differential Equation 1 below;

Please help me with following codes below

1. Boundary Condition 1
2. Boundary Condition 2
3. General Solution
4. The integration Part of the Equation
5. Solving the Differential Equation  

Equation 1.

Determine the equilibrium temperature for a one dimensional rod with a constant thermal properties with the following source and boundary conditions.

1. Q = 0, U(0) = 10, u(L) = 20
2. Q/K0 = x, u(0) = 0, u(L) = 10

I understand how to obtain the solution to the equation above,

(a) Equilibrium satisfies

                                                U’’(x) = 0,

Whose general solution is u = c1 + c2x.

The boundary condition u(0) = 0 implies c1 = 0 and u(L) = T implies c2 = T/L so that u = T x/L.

(f) In equilibrium, u satisfies

U’’(x) = −Q/K0 = −x^2,

Whose general solution (by integrating twice) is

u = −x ^4 /12 + c1 + c2x.

The boundary condition u(0) = T yields c1 = T, while u’(L) = 0 yields c2 = L^3/3.

Thus u = −x ^4 /12 + L^3x/3 + T.

I am trying to get jacobian computed for lorenz equations, not showing matrix, using Maple 2019 newest version. any guidance?

Hi everybody!

Quick question for you guys. I have access to Maple 2019 on my main computer and Maple 2018 on a remote Desktop (but I don't want to use because it's super slow and bad (normal rdp stuff)). The problem I have is for the same document, same line, same instruction, Maple 2019 on my computer is failling to do it correctly (unable to do the matrix correctly) and in the Remote Maple 2018 it's doing it just fine. I really don't understand. If someone can give me a little help it would be highly apreciated!

Maple 2018 (what it's supposed to do):

Maple 2019 (what it is not suppose to do):

restart;

with(DifferentialGeometry);
with(Tensor);

DGsetup([x, t], M1);

g := evalDG((dt &t dt) - t^2*(dx &t dx))
Geodesics()

I created a two dimensional cross-section of a spacetime described by this metric above. 

I would like to plot the geodesics in polar coordinates using the time t as the radius (normalized to our current time equal to unity).

That is, I would like to plot the geodesics starting at x=0, t=1 (x=0 maps to the top of the polar plot). X is the polar angle.

This plot is likely to map to this figure. Never mind the details of wiggles, or titles, etc.  I am new to maple and could use an initial push.