>P:=n->1/3*n^3 + 1/2*n^2 + 1/6*n; >factor(P(n)); This will give you the 6 in the denominator, but it will also simplify the numerator as well. I do not know if that is acceptable to you. Regards, Georgios Kokovidis

Greetings. geom3d does not work for your case. The routine finds the intersection between two lines, two planes, a line and a plane, a line and a sphere, or three planes. Using geom3d and your code, you can generate the equation for the sphere, and then solve for the intersection points. After that you can plot: >restart:Digits:=20:with(plots): >f:=(x,y,z)->x^2+y^2+z^2-5*x-5*y-14/3*z=0; >g:=(x,y,z)->z-4=0; >schnitt:=x,y,z; >solve({f(schnitt),g(schnitt)}); >evalf(allvalues(%)); >c1:=spacecurve([2.5+.16666*(321.0-36.0*t^2+180*t)^(0.5),t,4.0],t=-3..7.5,color=red,thickness=2,numpoints=3000): >c2:=spacecurve([2.5-.16666*(321.0-36.0*t^2+180*t)^(0.5),t,4.0],t=-3..7.5,color=red,thickness=2,numpoints=3000): >c3:=implicitplot3d({f(schnitt),g(schnitt)},x=-5..10,y=-5..10,z=-5..10,style=patchcontour): >display({c1,c2,c3},axes=framed,orientation=[-160,62]); >display({c1,c2},axes=framed,orientation=[-160,62]); Good luck with the tetraeder. You should be able to use geom3d to obtain the equation and then use the code example for the sphere as a starting point. The above was rather painful but it can be done.

Greetings. The intersection command will return, in the form of an equation, the intersection of certain objects. Those objects need to be defined in terms of equations as well. Is there a starting point for your sphere and plane in space, or is the origin acceptable. You mention that you know how to create the plot. Can you include the code that you used to do this? I need a starting point. Let me know either way and we'll take it from there. For now, see if the link below has something you can use: http://www.alpheratz.net/murison/Maple/SpherePlane/SpherePlane.html Regards, Georgios

>restart: >with(plottools): >with(plots): >a:=(tetrahedron([0,0,0],3)): >b:=sphere([0, 0, 0], 3): >display(a,b); Look into the help pages for plot and plottools. There you will find examples with more details, and an explanation of what the parameters for each of the commands are. Then you can scale the size and the position of each of the 3D plot objects to get a better picture of the intersection of the two. At the command prompt, type ?plot and then ?plottools for more information. Regards, Georgios Kokovidis Dräger Medical

For examples within Maple for contour plots in 2-D or 3-D, try the help pages first: >?contourplot If you are looking to do something else, please be a little bit more specific with the exact problem you are trying to solve. Regards, Georgios Kokovidis

At the Maple prompt, type the following, and look at the associataed help pages to see if it helps: >?orthopoly[P] In order to use the package, you must load it. Then, you can obtain P5(x) as shown below: >with(orthopoly): >P(5,x); The output is: 63/8*x^5-35/4*x^3+15/8*x Regards, Georgios Kokovidis Dräger Medical

This is from a previous thread. See if it helps. http://www.mapleprimes.com/forum/labeling-level-curves Regards, Georgios Kokovidis

> restart: > eq1:=(1+j/365)^365=1.1; > solve(eq1,j); There is one real answer and the others are all complex. Using fsolve, you can do it like this. Notice the zeros after each of the numbers, forcing them to be floats. > restart: > fsolve((1.0+j/365.0)^365.0=1.1,j); Regards, Georgios Kokovidis

Take a look at the applications center: http://www.maplesoft.com/applications/index.aspx and click on Mathematics, as well as the student center: http://www.maplesoft.com/academic/students/index.aspx Regards, Georgios Kokovidis

Try replacing your line yn:=dsolve({eqs,ic},{y1(x),y2(x),y3(x)}): with yn:=dsolve({eqs,ic},[y1(x),y2(x),y3(x)]): and see if it will do what you want. This will declare your variables as a list instead of a set and the output should be the same every time. Regards, Georgios Kokovidis

Sort how? What exactly are you trying to do? Below is an example with sort. The numbers are sorted in ascending order from smallest to largest. > a:=1-sqrt(3.);c:=1-sqrt(5.);b:=1+sqrt(7.);d:=1-sqrt(7.); > sort([a,b,c,d]); [-1.645751311, -1.236067977, -.732050808, 3.645751311] Do a search within Mapleprimes as well on sort. Regards, Georgios Kokovidis

> restart:with(DEtools): > odeqs:= {diff(N(t),t) = a*N(t) - b*N(t)*P(t), diff(P(t),t)=c*N(t)*P(t) - d*P(t)}: > a:= 3; > b:= 2; > c:= 1; > d:= 1/2; > initConds:=[[N(0)=(5/3),P(0)=(10/9)]]; > DEplot(odeqs, [N(t),P(t)], t=0..100, N=0..7, P=0..7, initConds,stepsize=0.05,scene=[N(t),P(t)]); I noticed in your posting that the last line of your code had a colon instead of a semicolon. This will give you an empty plot. Regards, Georgios Kokovidis

This is not possible. There are too many factors. 1: Does the problem of interest have a solution? Numeric or symbolic for that matter. 2: What type of machine is the problem run on? 3: Some people use distributed computing, where a big problem is broken up and run on multiple machines. I am assuming this is not your particular case, but it will determine computation time. Post your particular problem with the exact code if possible. Maybe there is something in your code that is causing Maple to compute for so long without a solution. Regards, Georgios Kokovidis

From a previous posting here at Mapleprimes: http://www.mapleprimes.com/forum/finding-largest-entry-in-a-matrix Regards, Georgios Kokovidis

The link below might be helpful to you for the types of problems that you are working on. Just cut and paste into your browser. www.rose-hulman.edu/Users/groups/packets/HTML/modern/maplepg.htm#LGHTBULB.MS Regards, Georgios Kokovidis