## Discontinuous 3D-plot...

Hi. I'm trying to make a 3D-plot of a function f(x,y) that is discontinuous but can not figure out how to do it. I'm new to Maple but I found that there's an option discont=true for 2D-plots. Something similar for 3D? Cheers

## I want clear just some variable Not all of them???...

Hi, I want clear some variable Not all of them in my program(restart command clear all of them), is it possible in Maple to do that?Tanx.

## Root Finding...

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.

## matrices of boolean variables

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

Thanks

## Finding turning point, intersection of functions...

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

## question about fractional form / evaluating cfrac ...

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 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