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Hi

 I have the following ODEs

Restart:
a:=0.13:
b:=0.41:
reynolds:=1.125*10^8:
Eq1:=diff(f(x),x$3)+diff(f(x),x$2)*f(x)+b^2*sqrt(2*reynolds)*diff(diff(f(x),x$2)*f(x)*x^2,x$1);
Eq2:=diff(g(x),x$3)+diff(g(x),x$2)*g(x)+c*a^2*sqrt(2*reynolds)*diff(diff(g(x),x$2)*x,x$1);
f(0)=0;
D(f(0)):=0;
# continuity condition  
g(0.1*c)=f(0.1*c):
D(g(0.1*c))=D(f(0.1*c)):
(D@2)(g(0.1*c))=(D@2)(f(0.1*c)):

the value of c is unknown which must be obtained via D(g(c)):=1;

 How can I solve it?

Thanks for your attentions in advance

Amir

I downloaded Maple 17 student eddition for linux and when I click on the bin file to install it I get an error that says "This file is of unknown type". It gives the option to find an aplication local or online and it says no aplications available or the "MIME" file type canot be installed on this system. Im not sure what to do, do I need somthing to unpack the file or is it just not aplicable on my linux operating system (version: Cinnamon version 1.8.8 LinuxMint: olivia(X86-64))?

Hi

i want to minimizez the "Eq1(h[1],h[2],...h[n])" for all the h[i] in the ranges of -1<h[i]<1.  "n" (number of unknown variables) can be determined during the code and was not know before. how can i do this?

It must be stated that when i have Eq1 and two unknown variables such as h[1] and h[2], i wrote the following code and it works good, but i dont know how can i write mentioned command for unknown number of variables.

NLPSolve(Eq1,h[1]=-1..1,h[2]=-1..1);

thanks for your attention in advance

Hi,

Suppose you have an unknown function y(x)  that is 2*Pi periodic, i.e. (y(0) = y(2*Pi)). Is there a way to declare this in Maple? The reason I want to do this, is that if I integrate the derivative y'(x) of  this unknown function on [0,2*Pi]I would like Maple maple to be able to recognize that:

 

int(y'(x),x=0..2*Pi) =0

 

Thanks

Hi,

I am trying to solve the following system using the function "solve", but the message "warning solutions may have been lost" appears.

 

This is my script (a,b,c,d,e,f, Resp, Malcyt,Pyrcyt are parameters). The unknown variables are Citcyt, Citmt,Malmt,Pyrmt:

e1 := 0 = a.Pyrcyt-a.Pyrmt+(b-c).Malmt;
e2 := 0 = d.Malcyt+e.Citmt-(d+b+c).Malmt;
e3 := 0 = f.Citcyt+c.Malmt-(e+f).Citmt;
 e4 := 0 = 2.*e.Citmt+(b+c).Malmt-Resp;

Hi all,

Is there a quicker way to find all unknows from an expression?

unknowns.mw

Say I want a list contains ALL parameters. In this case, it would return

[w1,w2,mu,tau[2],tan[3],tan[4],eta[1],eta[2]]


Is there a way to do this?

Thanks!

Casper

Hey Guys,

I'm trying to solve a system of 5 linear equations to get 5 unknowns:

well first of all this site was very useful for doing my homework, but there is still something I didnt find on it and im sure other people may find it useful.

 

I have a system of 5 ode's and 6 initial conditions that ive solved successfully and plotted the graphs i need:  Position VS Time

          Speed VS Time

The only thing I initially know is the final position, which i can read on the first graph and...

Good Morning.

 

I have a problem

i have two functions

> xcir(t):=0.3 + 0.15*sin(t):
> ycir(t):= -0.3-0.15*cos(t):
 
and i suppose that i have a problem in the following equation
> qd2 := ((arctan(-ycir(t)/xcir(t))-arctan(.45*sin(qd3(t))/(.45+.45*cos(qd3(t)))))*180)/(3.1416);
> qd3 := 180*arccos((xcir(t)*xcir(t)+ycir(t)*ycir(t)-.45*(2*.45))/(.45*(2*.45)))/(3.1416);
 

Good Morning.

I have problem when i want to graph my equations. I received this error: 

Error, (in plots/odeplot) curve is not fully specified in terms of the ODE solution, found additional unknowns {t}
I would like to know how i can solve it
Thanks in advance 

...

I have just tried to solve for 2 equations in 2 unknowns. The 2 equations are very non-linear. I know for a fact that there are 2 solutions as I can draw the curve, but for some reason and for some parameter specifications Maple will only give me 1 out of the 2 solutions. I use the following:

 

Solve( [eq1,eq2] , [x,y])

 

Thanks in advance,

 

Christian

Hi,

 

I need to find the eigenvectors of this matrix and get the following error:


> eigenvects(A);
 linalg:-eigenvects called with arguments: [[200, -96, 5, -4.4, 4.7, -12.6, -6.2], [-96, 320, 33.1, 6.8, 4.5, 7.4, -.3], [5, 33.1, z, -51.1, .8, -8.4, 7.6], [-4.4, 6.8, -51.1, 110, -76.6, -14.2, -67], [4.7, 4.5, .8, -76.6, 270, 78.3, -.1], [-12.6, 7.4, -8.4, -14.2, 78.3, 420, 38.3], [-6.2, -.3, 7.6, -67, -.1, 38.3, 230]]
 #(linalg:-eigenvects,7...

as you know the number of solutions for order 3 to 5 magic squares is as follow : 
(not counting rotations and reflections)

order 3: 1 solution

order 4: 880 solutions

order 5: 275305224 solutions

higher order: unknown ...

 

in the first look at 880 , simply appeared it can constructed by
2x5x8x11 (every factor increased by 3)

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