I have a problem:
I have an ODE, dT/dy, that depends on y and k, but k itself depends on rho and T. The only problem is rho cannot be obtained analytically--it's a complicated function. However, I can use a rootfinding algorithm,(fsolve), to determine rho at given values of y, thereby making my ODE solvable. I want to use dsolve to numerically solve this ode. The problem is I can't seem to be able to input the fsolve equation as an argument to the dsolve command. It keeps telling me :
Error in fsolve, y is not solved for. But my intention is to use y to solve for T and rho in dsolve. If anyone has any idea I would greatly appreciate it.

How can I declare a matrix of boolean variables, and later perform logical operations.

Thanks

Hi people, I have two questions and help on any of them would be greatly appreciated.
1. My first question is how would i find the point(s) where the two equations intersect?
eg.
4*(x-1)^2+(y-2)^2 = 5;
x^2+4*y^2 = 1;
2. My second question is how do i find the turning points of a function?
eg.
x*cos(x^2)/(1+x^2)
Again any help is really appreciated. Thanks in advance.

Hey guys
Does anyone know how to include an fsolve command incorporated into the dsolve command?
In other words, as dsolve iterates the runge kutta procedure, it uses the inital values to use fsolve which would then be used over again in the rk procedure..
Thanks
B-rad

Where can I find a description for the various variants of numtheory:-cfrac,
which goes more into details than the online help? For example one can guess
how an approximating sum can be obtained from
numtheory:-cfrac((a+x)^k, x, 7, 'diag', 'simregular', 'quotients');
but I prefer to cross-check against a confirmed formula
instead of guessing.
If somebody would be so kind to point me to some source to look at ... or
even knows it already ...:
how does one evaluate the above list to get a value?
--
edited to add: I mean a way which can be compiled and without running through

Does it surprise anyone that Maple can't run a loop from i=10^8 to i=10^9 ? Or is my computer just too slow?
Thanks
Brandon

Does anyone know how to incorporate a rootfinding algorithm with a numerical dsolve? What I mean is to solve an ODE numerically, but having to use a rootfinding technique at the same time... Thanks for your input guys, Brado

Hi guys, I just have a quick question: Does anyone know if there is a way to access to actual code Maple uses for solving ode's numerically? Like, for instance, if you use the Runge-Kutta method and you use dsolve(numeric), is there anyone to actually see the code that Maple uses to calculate the ODE? Because I need to add something inside the loop used to solve the ODE. If anyone knows an easier way to add something to the method that Maple uses to solve ODE's numerically, I'd love to know!!! Thanks guys, Brandon

3 equations are: diff(u_r(r,theta),r)+2/r*u_r(r,theta)+1/r*diff(u_theta(r,theta),theta)+cos(theta)/sin(theta)/r*u_theta(r,theta)=0; -diff(p(r,theta),r)+mu*(diff(u_r(r,theta),r,r)+2/r*diff(u_r(r,theta),r)-2/r^2*u_r(r,theta)+1/r^2*diff(u_r(r,theta),theta,theta)+cos(theta)/sin(theta)/r^2*diff(u_r(r,theta),theta)-2/r^2*diff(u_theta(r,theta),theta)-2*cos(theta)/sin(theta)/r^2*u_theta(r,theta))=0; -1/r*diff(p(r,theta),theta)+mu*(diff(u_theta(r,theta),r,r)+2/r*diff(u_theta(r,theta),r)-1/(r^2*sin(theta)^2)*u_theta(r,theta)+1/r^2*diff(u_theta(r,theta),theta,theta)+cos(theta)/sin(theta)/r^2*diff(u_theta(r,theta),theta)+2/r^2*diff(u_r(r,theta),theta))=0;

i need to evaluate the expration
>beta=Pi/10;
>gamma=(Pi^2)/(2*beta*(Pi-2*beta));
>h=(1-(2*sinh(x*gamma*beta)*sinh(x*gamma(Pi/2-beta))))/(sinh(Pi*x*gamma/2)*tanh(Pi*x));
>int(tanh(Pi*x)/x*h(x)*LegendreP(-.5+I*x,1,cosh(2))^2,x = .1e-2 .. 3
thanks

Hi
I don't know how transfer a FUNCTION Such as X(T) FROM MAPLE TO MATLAB.
I SOLVED A DIFFERENTIAL EQUATION THAT MATLAB COULDN'T SOLVE IT,BUT MAPLE SOLVED IT WITH NUMERICAL SOLUTION,I EXTRACT X(t) BY USE OF LISTPROCEDURE AND SUBS COMMAND,NOW I HAVE A VARIABLE X(t) ,SUCH AZ X(1)=0.326 OR
X(100)=0.3685 ...
HOW CAN I USE X(t) IN MATLAB?Tanx.

Hello Everybody,
I have a question regarding intregration.
I am trying to integrate the follwing equation with respect to E with limits from k to E0 ( where E0 is 5.7) and expecting to obtain an equation only in k.
P1 := .97895*.38888e-1^(-.22310e-1+.38888e-1*ln(1-.17544*E))/(-.57371+ln(1-.17544*E))/k*(1.3557-1.3557*k/E+k^2/E^2)
I have tried hard but couldnt do it , somebody please help me !
Thanks in advance ! I appreciate it !
Regards,
Thomas !

In Discontinuous Galerkin Method and Finite Volume Method, 1d and 2d Rieman solver must be employed to get the flux between the adjcent elements.Does maple have the function to solve such Rieman problems? Thanks for ur reply!

I'll start off by saying that I suck at rearranging equations and doing complex maths... which is why I use Maple :) (I've got an old copy of Maple 8, which I use rather infrequently since it's not often I need to calculate complex equations). Right now, I have the equations below: S1 := ((R+(D1*sin(90-x)))^2+(D1*cos(90-x))^2)^(1/2); S2 := ((R-(D2*cos(x)))^2+(D2*sin(x))^2)^(1/2); eqn := (L1/(k*(S1^2)) + L2/(k*(S2^2)))^(1/4) = T; I need to make R the subject of the last equation (R is contained in S1 and S2). To do this I'm assuming that I just need to type "solve (eqn, {R});" to make R the subject but if I do that, I get this:

With this Generation of MapleStudio you can also plot complex functions in 2D and also 3D. For doing this, MapleStudio uses the **conformal **and the** conformal3d** comands of Maple 10. The following example will show you, how it works.