I am trying to solve the rate equations for A<=>B<=>C with k1,k2,k3,k4 as the rate constants.  I put in the equations into Maple but can't seem to get it to solve them.  The initial conditions for A(0) = S, B(0)=C(0)=0

Here is what I plugged into the program:

Parameters(S, k1, k2, k3, k4);

sys_ode := d*A(t)/dt = -k1*A(t)+k2*B(t), d*B(t)/dt = k1*A(t)+(-k2-k3)*B(t)+k4*C(t), d*C(t)/dt = k3*B(t)-k4*C(t);

d A(t)
------ = -k1 A(t) + k2 B(t),
dt

d B(t)
------ = k1 A(t) + (-k2 - k3) B(t) + k4 C(t),
dt

d C(t)
------ = k3 B(t) - k4 C(t)
dt

ics := A(0) = S, B(0) = 0, C(0) = 0;
A(0) = S, B(0) = 0, C(0) = 0

dsolve({ics, sys_ode});
Error, (in dsolve) found functions with same name but depending on different arguments in the given DE system: . It is required an indication of the dependent variables

I have to questions. One is the main one, about simplifying fractions.

This is equations.

jj:=L*theta*gamma[2]^2*(-1+alpha)/(delta[2]*(-alpha*gamma[1]^(-2*sigma+2)*gamma[2]^(2*sigma)-gamma[2]^2+gamma[2]^2*alpha));

kk:=expand(denom(jj)/gamma[2]^2);

ll:=op(1,kk);

mm:=simplify(ll,power);

nn:=mm-delta[2]+delta[2]*alpha;

oo:=numer(jj)/gamma[2]^2/nn;

pp:=(numer(jj)/gamma[2]^2)/(denom(jj)/gamma[2]^2);

From now, I will explain. Though as I don't know how to put a maple screen on this board I think I will have you feel some inconvenience, please forgive it.

I want to make jj more simple, dividing both of numerator and denominator of jj, with gamma[2]^2.

But, what I could at best was this. First, taking denominator of jj and deviding it with gamma[2]^2 and expanding it like kk. Second, as the first term among that expression had terms of gamma[2] on both of the numer and denom, I picked out the first term as ll in the above maple commands, and simplified it with option: power, in mm. Thirdly, I rewrote kk as in nn.

and Forthly, I rewrote jj with modification of deviding numerator and denominator with gamma[2]^2, using the result which I could get as I wrote above. oo is that. And the result of oo is what I wanted to get.

But, on the other hand, when i divided denom and numer of jj directly by gamma[2]^2, the result I can get then is not 

good one: the output of pp is not what I wanted to get.

Is there more simple way to do what I did in the above? This is a first question.

And, another is how I can post the screen of maple on this question board?

I hope you will answer my question. I thank all of you who will answer these question in advance.

Hellp

for a task about the launch of a rocket we had to make a matrix OPL3 with in the first column the time T and in the second column the height of the rocket at that time.

I must Maple find the time where the rocket is at his highest point.

I can find how high the highest point is, but didn't succeed to find the corresponding time.
Can Maple tell me at wich time (= row # o/t matrix OPL3) the rocket is at his highest point.

I used the following to find the highest point.

ymin:=min(seq(abs(OPL3(i,2)),i=64..830));

Note: the diff equitation is numerically solved, so I can't use solve(....=0) (am I right here?)

Thanks!

How  can you create a loop for Monty Hall Problem when you have 3 door (1 opening) and then 4 Doors (with 2 openings and possible 2 switches)

I have this kind of problem. When I try to solve my command:

is there any way to avoid this? in order to get the answer directly...

I encounter "insufficient  initial/boundary value" error message,  do know how to proceed from there, search with "insufficient initial value" gets no result. Any help will be appreciated.

> restart; alias(r = r(t), f = f(t)); with(plots);
r, f
> DE := diff(r, t) = 2*r+alpha*r*f, diff(f, t) = -f+alpha*r*f;
d d
--- r = 2 r + alpha r f, --- f = -f + alpha r f
dt dt
> NULL;
> params := alpha = .3;
alpha = 0.3
> initv := r(0) = 101, f(0) = 2;
> NULL;
>
> dvars := [r, t];
> chaodisplay := proc (chartname) EQ := [op(subs(params, [DE])), initv]; EQ1 := dsolve(EQ, numeric); odeplot(EQ1, dvars, t = 0 .. 300, axes = frame, numpoints = 50000, color = green, orientation = [-30, 100], title = chartname) end proc;
Warning, `EQ` is implicitly declared local to procedure `chaodisplay`
Warning, `EQ1` is implicitly declared local to procedure `chaodisplay`
>
> chaodisplay("Rabbit and Fox");
Error, (in dsolve/numeric/type_check) insufficient initial/boundary value information for procedure defined problem
>

Dear people being here,

I have a question.

When I wrote as

aa:=(delta[1]*n[1])/(n[f1]*delta[1]);

maple returned as 

aa := n[1]/n[f1]

How can I have maple express the original one, aa:=(delta[1]*n[1])/(n[f1]*delta[1]), not what returned to me?

I hope you will answer to my question.

And, thanks in advance.

taro

Please help me, here my problem:

Parsing a string works correctely like this:

ABC := 3443;

print("ABC = ", eval(parse(cat("A", "B", "C"))));

But using PROCEDURE it doesn't work:

myParse := proc ()

     local PEA;
   

      PEA := 4334;

      print("PEA = ", eval(parse(cat("P", "E", "A"))))

end proc;

myParse();

                        "PEA = ", PEA

I suppose to have "PEA = ", 4334

how to make a table of newton raphson ? 
working is below 
printf("No           root                   x[i+1]                 abs(x[i+1]-x[i])\n"); for i to n do y[i] := evalf(x[i]+(-D1(x[i])+sqrt(D1(x[i])^2-2*f(x[i])*D2(x[i])))/D2(x[i])); x[i+1] := evalf(y[i]-f(y[i])/sqrt(D1(x[i])^2-2*f(x[i])*D2(x[i]))); printf("%d         %10.10f     %10.10f       %10.10e \n", i+1, x[i+1], f(x[i+1]), abs(x[i+1]-x[i])); if abs(x[i+1]-x[i]) < tol then print("approximate solution" = x[i+1]); print("No of iterations" = i+1); break end if end do
please help me 

Hi, I need to show some how by using Maple, that n^3>(n+1)^2 where n>=3. Iam new at Maple and not sure how I can graph inequality as n goes to infinity. Any help would be appriciated. Thanks!!!

I'm asked to solve the equations below simultaneously using fsolve.

f := x*exp((1 - x)*a);
f[2] := subs(x=f,f);
eq[1] := f[2] - x;
eq[2] := diff(f[2],x) + 1;

fsolve({eq[1],eq[2]},{x,a}):

fsolve doesn't seem to work here for some reason.

Any help help would be great!

Thanks

Hi Everybody,

I'm having some problems simulating an algebraic system in Maple.  I want to do this for a larger system of equation (~20 equations/20 variables, with 3 inputs), but I'd like to get an idea of the form this should be in.

So, using an example out of Maple help:

with(DynamicSystems);

sys1:=AlgEquation([y=sin(x)],[x],[y],discrete=true,sampletime=0.001);

inp1:=Vector[column]([1,2,3,4,5,6,7]) * 0.1;

res:=Simulate(sys1,[inp1]);

Error, (in DynamicSystems:-Simulate) should never be here

 

I don't understand what this error means.  Reading the example in the help files, says the second argument should be a vector of input values.  What I would assume this would do is plugin x = 0.1, then solve y=sin(0.1), and output y.

Am I missing some syntax, or is my inputs wrong?  There are examples of how to set up an algebraic system in the help files, but no examples of how to simulate them.

Thanks in advance for any help!

Hello all. I have a probably simple problem, that is drinving me totally crazy. I have a expression having:

 (sqrt(M+m)*sqrt(M-m).(sqrt(M+m)*sqrt(M-m))

and it refuses to simplify. I told maple assume(m>0, M>0), etc. But it doesn't want to simplify. Anyone has any ideas?

Regards,

Jelmew

Edit: uploaded the mw file, so it can be seen what the problem is.10.1.mw10.1.mw

[I added Physics to the tags.--Carl Love as moderator]

Hi, i'm trying to solve the simultaneous equations,

a[1]:=2*x^2 + 3*x^2 + x*y - x^2 + x;

a[2]:=3*y^2 + 4*x^2 - y;

eval(y,fsolve({a[1],a[2]},{x,y}));
0.

Even though y can be 0 it can also be 1/3 and two other complex numbers.

How do you get fsolve to show all four y solutions.

Secondly, how would i get maple to just to show the positive y solution ie. 1/3 only.

Hello,
my question may be simple but I don't find the answer in any help guide.
when I define a function I cannot use a linearalgebra expression such as Trace.
Here is an example of what I would like to do:

If anyone can help me...
Thank you