MaplePrimes Questions

How to make a vertical axis of the plot break?

Hi:

how i find the roots of the below equation?

eq := tan((1/2)*x)-tanh((1/2)*x) = 0

 

c1 := circle([0, 0], 1, color = red);
p2 := implicitplot(x = 1/2, x = -2 .. 2, y = -1 .. 1.1, colour = blue, linestyle = 1, thickness = 2);
display(c1, p2);

How to fill that part beetween line and circle(where x>1/2 in circle )?

This is an addition to the following post:

http://www.mapleprimes.com/questions/141795-Unit-Conversion-Problem

 

But I use the clickable facilities of Maple.  Here is the problem:

>32[[degC]];

                         32[[degC]]
right-click -> Units -> Replace units -> degF

                         288           
                         --- [[degF]]
                          5            

>evalf[5]( (2) );
                       57.600[[degF]]

but if I do that:


>convert(32, 'temperature', 'degC', 'degF');

                              448
                              ---
                               5
                           
>evalf[5]( (4) );
                             89.600

Why the conversion is bad when you try to do it by the clickable way????????????

 

--------------------------------------
Mario Lemelin
Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 - 64 bits messagerie : mario.lemelin@cgocable.ca téléphone :  (819) 376-0987

In order to make worksheets more interactive in a teaching environment I have begun playing around with the Tables the standard GUI provides. The idea is that in the left column is the script we are working through while in the right column is space a student can work with the equations and formulae from the left side to, e.g., plot, change parameters etc. without affecting the script too much.

To build the tables I copy-pasted code from a normal worksheet (in document mode) into the left column, creating rows of appropriate length to have a logically coherent section in one row. Usually one row is one Section (in the technical sense of Maple Sections). The student gets to play in the right column.

In principle this seems to work quite well in my preliminary testing. I did find out rather quickly that on the right side one needs to be in 1-d input mode with a prompt for anything to be calculated interactively. Ok, actually probably easier to do. The table is set to evaluate by row so the right-left correspondence is preserved.

A potential issue I am facing however is with equation numbering: I use equation numbers extensively to reference back to upstream results. In the Table, it appears that equation numbers are not unique; in each row of the Table, eq. numbers start as (1.1), (1.2) etc. I am able to reference back to results from a prior row, even though the same equation number will show up again later in the new row. But I am concerned that eventually this all ends up in a big mess and my references point to the wrong expression or equation. Non-unique line numbers seem like a Really Bad Idea, and I'd like to avoid that if possible.

Does anyone know how the lines numbers work for code in Tables and how I make sure they are unique? I suppose I could explicitly assign results I need in other rows to names, but that does not prevent a reference to an eq. number from pulling in the wrong one from a prior row (assuming for the moment that Maple will never look forward to resolve a reference).

Thanks,

Mac Dude

ode := diff(sqrt(U(t)), t) = sqrt(U__0)-sqrt(U(t))

ics := U(0) = 0

dsolve({ics, ode})

 

And the result maple returns is U(t)=0 !

 

 

Diff_EQ_sample_questions.pdf

 

This is a link to two sample questions I am trying to learn how to solve using maple. I am using maple student edition of maple. Any help would be great. Thank you.

 

 

Why does:

Student[Calculus1]:-Tangent(tan(3*x)-5*exp(-x^3),x=0,output=plot,gridlines=true,caption="")

produce the following error?

Error, (in plots:-display) integer or integer range expected in op list

i have a non linear equation that depends on three variables e, theta and z.

i have done calculations to calculate e while varying theta and z. theta varied among the vector [0, Pi/4, Pi/3, Pi/2] and z was varying between 1 and 20

when plotting my data it gives the following plot where z is represented on the x-axis and each curve correspond to one theta

 

i am currently able of fitting one plot to one equation i would like to fit the data points using the nonlinearfit function and to only get one equation for all the plots. is that possible in maple or not

 

I am having an issue with Physics[Vectors] in Maple 17, specifically an interference with PDEtools:-dchange. My apologies, this post is lengthy & a bit messy. I did upload a worksheet with the code; link at the end. The upload exhibits the UNWANTED behaviour in Maple 17.

Here are a few lines of code that exhibit the WANTED behaviour (change of variable and solving a de). it is run in Maple17 with Physics loaded but NOT Physics[Vectors]. The paste into Mapleprimes looks too messy to be useful so I am just showing the relevant lines; the file has everything:

-(diff(E1_(x, y, z, t), x, x))-(diff(E1_(x, y, z, t), y, y))-(diff(E1_(x, y, z, t), z, z)) = -mu*epsilon*(diff(E1_(x, y, z, t), t, t));

PDEtools:-dchange({x = r*cos(theta), z = r*sin(theta)}, -(diff(diff(E1_(x, y, z, t), x), x))-(diff(diff(E1_(x, y, z, t), y), y))-(diff(diff(E1_(x, y, z, t), z), z)) = -mu*epsilon*(diff(diff(E1_(x, y, z, t), t), t)), simplify);

subs(E1_(r, theta, y, t) = R(r)*exp(I*(-k*y+omega*t)), -((diff(diff(E1_(r, theta, y, t), y), y))*r^2+(diff(diff(E1_(r, theta, y, t), r), r))*r^2+(diff(E1_(r, theta, y, t), r))*r+diff(diff(E1_(r, theta, y, t), theta), theta))/r^2 = -mu*epsilon*(diff(diff(E1_(r, theta, y, t), t), t)));

dsolve((5));

So far this is all as expected.

Now I rerun this thing with Physics[Vectors] loaded rather than just Physics. Everything looks the same until I get to the line starting with subs(E1_ :

subs(E1_(r, theta, y, t) = R(r)*exp(I*(-k*y+omega*t)), -((diff(diff(E1_(r, theta, y, t), y), y))*r^2+(diff(diff(E1_(r, theta, y, t), r), r))*r^2+(diff(E1_(r, theta, y, t), r))*r+diff(diff(E1_(r, theta, y, t), theta), theta))/r^2 = -mu*epsilon*(diff(diff(E1_(r, theta, y, t), t), t)));

plus many more lines of expressions. I am not sure what is going wrong; but after the dchange the code behaves funky: I have had simplify producing similarly weird expressions etc.

Note that on Maple 15 this all works as expected and no issues show up for me. If the version of Physics I have on Maple 17.02 is bad; how do I change that? (I have not tried to update Physics separately, and it isn't obvious to me where to find it for Maple 17). It is sort-of an issue as I want to use this as a demo for students, who in fact will be running Maple 18... but I am stuck at 17 (and often using 15 at home) so I need this to work there (17), too.

TIA,

Mac Dude

dchangeTest.mw

 

AOA... Dears! When i solve the following differential equations

-(diff(lambda(s), s))-2*(diff(lambda(s), s, s))-(diff(lambda(s), s, s, s)) = 0

i got

lambda(s) = _C1+_C2*exp(-s)+_C3*exp(-s)*s

 here _C1,_C2 and _C3 are constant of intergration but i want the constant of integration of the following type

C[1],C[2] and C[3]

due to some reson pl help

Hi,

I have written a for-end loop and put all the outcomes of the loop in a matrix and now I want to plot these results but for some reason maple won't plot the matrix in a correct way. If I copy-paste the matrix into an new file maple plots it correct. What is the reason that maple won't plot it in my original file?

Here is my file. 

restart;
Parameters
L := 20; Q := 20; n := 8; h := 3; EAv := 1;
Mat := Matrix(10, 2, storage = sparse);
a := 1;
loop L1
for L1 from .6 by .1 to 1.5 do
L1 := L1;
L2 := 2*L1;
L3 := 1.6*L2;
L4 := (1/2)*L-L1-L2-L3;
alfa1 := evalf(arctan(h/L1));
alfa2 := evalf(arctan(h/L2));
alfa3 := evalf(arctan(h/L3));
alfa4 := evalf(arctan(h/L4));
F4 := (1/2)*Q*L4;
F3 := (1/2)*Q*L3+(1/2)*Q*L4+F4;
F2 := (1/2)*Q*L2+(1/2)*Q*L3+F3;
F1 := (1/2)*Q*L1+(1/2)*Q*L2+F2;
w1 := evalf((1+sin(alfa1)^3)*F1*L1/(EAv*sin(alfa1)^2*cos(alfa1)));
w2 := evalf((1+sin(alfa2)^3)*F2*L2/(EAv*sin(alfa2)^2*cos(alfa2)));
w3 := evalf((1+sin(alfa3)^3)*F3*L3/(EAv*sin(alfa3)^2*cos(alfa3)));
w4 := evalf((1+sin(alfa4)^3)*F4*L4/(EAv*sin(alfa4)^2*cos(alfa4)));
kkm := (w1-w2)^2+(w2-w3)^2+(w3-w4)^2; Mat(a, 1) := L1;
Mat(a, 2) := kkm;
a := a+1
end do;

with(plots);
pointplot(Mat);

 

Hi,

I have this set of equations but maple won't solve the three variables and it gives an 

Error, (in solve) cannot solve for an unknown function with other operations in its arguments. This are the equations with unknowns, alfa1, alfa2, and alfa3.

eq1 := 3*(1+sin(alfa1)^3)(30/tan(alfa1)+60/tan(alfa2)+60/tan(alfa3))/(sin(alfa1)^2*cos(alfa1)*tan(alfa1)) = 3*(1+sin(alfa2)^3)(30/tan(alfa2)+60/tan(alfa3))/(sin(alfa2)^2*cos(alfa2)*tan(alfa2));

eq2 := 3*(1+sin(alfa1)^3)(30/tan(alfa1)+60/tan(alfa2)+60/tan(alfa3))/(sin(alfa1)^2*cos(alfa1)*tan(alfa1)) = (90*(1+sin(alfa3)^3))/(sin(alfa3)^2*cos(alfa3)*tan(alfa3));

eq3 := 3/tan(alfa1)+3/tan(alfa2)+3/tan(alfa3) = 25/2;

solutions := [solve({eq1, eq2, eq3, alfa1 > 0, alfa2 > 0, alfa3 > 0}, {alfa1, alfa2, alfa3})];

Can anyone help?

 

How can I solve a differential equation set of the type,

dy(x)/dx +y^2 =P(x); dP(x)/dx = R(P) numerically

Hi all,

As we know that the indefinite integral in Maple is defined up to a piecewise constant.

For example,

 

Due to the indeterminate range of variable n, int returns the piecewise function.

But in the other similar case, we get a generic solution rather than a piecewise function,

 

Why not to returns the result like this,

 

Thanks for any help.

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