## Does it surprise you.....

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.....

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

## Can anyone help me?...

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;

## lagendre with complex degree...

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

## Data Transfer From Maple To Matlab...

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.

## Integrating with one variable in a two variable eq...

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!

## Want to solve equation, need help interpreting res...

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:

## HELP!!!!!...

I need some help guys!! I solved 3 simultaneous ODE's using dsolve, and everything went well. But how do I access the variables after? Like if you solve an ODE with dsolve, let's say y'(x) = x after dsolve solve's it, how do you then use y or x? Thanks!!!

## cos(Pi/17) in terms of exact radicals...

How can I find the exact solution? > a20:=cos(Pi/17) = sqrt(sqrt(38*sqrt(17) + 170) + 3*sqrt(17) + 17)/8 + sqrt(34 - 2*sqrt(17))/16 - sqrt(17)/16 + 1/16: > evalf(a20); 0.9829730997 = 0.9829730994 I found cos(Pi/5) and cos(Pi/15). a1:=cos(Pi - 2*Pi/5) = cos(3*Pi/5): > a2:=cos(Pi - 2*x) = cos(3*x); a2 := -cos(2 x) = cos(3 x) > a3:=expand(a2); 2 3 a3 := -2 cos(x) + 1 = 4 cos(x) - 3 cos(x) > a4:=subs(cos(x)=y,a3); 2 3 a4 := -2 y + 1 = 4 y - 3 y > a5:=[solve(a4,y)]; 1/2 1/2 5 5 a5 := [-1, ---- + 1/4, 1/4 - ----] 4 4 > a6:=cos(Pi/5)=a5[2]; a6 := cos(1/5*Pi) = 1/4*5^(1/2)+1/4 > evalf(a6); 0.8090169943 = 0.8090169942 > a7:=cos(Pi/3-2*Pi/5)=cos(Pi/15): > a8:=cos(Pi/3-2*x)=cos(Pi/15): > a9:=expand(a8); a9 := cos(x)^2-1/2+3^(1/2)*sin(x)*cos(x) = cos(1/15*Pi) > a10:=subs(sin(x)=sqrt(1-cos(x)^2),a9); a10 := cos(x)^2-1/2+3^(1/2)*(1-cos(x)^2)^(1/2)*cos(x) = cos(1/15*Pi) > a11:=subs(cos(x)=a5[2],a10): > a12:=simplify(expand(a11)); a12 := -1/8+1/8*5^(1/2)+1/16*3^(1/2)*(10-2*5^(1/2))^(1/2)*5^(1/2)+1/16*3^(1/2)*(10-2*5^(1/2))^(1/2) = cos(1/15*Pi) > evalf(a12); 0.9781476005 = 0.9781476007 I have a simplier version. > a13:=sqrt(6*sqrt(5) + 30)/8 + sqrt(5)/8 - 1/8 = cos(Pi/15): > evalf(a13); 0.9781476010 = 0.9781476007

## About Green Equation and Gauss...

I am new to maple. At present, i am do some study on FEM. so i want to ask if there is some command in maple about the fomulation of Green and Gauss theorem. for i want to change to the body integral to the boundary integral. Thanks for your reply!