## arranging terms by degree...

when expanding an expression like (x+1)^7*(x-2)^9, how do arrange the terms by increasing/decreasing degree? ie ax^16+bx^15+cx^14+...

## Periodic Functions...

Is there a way to create periodic piecewise functions in Maple 10 for use in solving differential equations with periodic forcing functions?

## Duhamel's Convolution Principle...

I've been trying to find information about this apparently elusive (or perhaps obscure) topic without a lot of luck. I was curious if anyone had ever heard of a technique for solving an nth-order nonhomogeneous linear ODE with constant coefficients by means of Duhamel's Convolution Principle. The guy who taught this technique to me didn't believe in using textbooks (or staying in accordance with predefined curricula) and he basically just taught whatever he wanted. He essentially claimed that any nth-order nonhomogeneous linear ODE with constant coefficients could be solved by first solving the associated homogeneous equation, and then, writing a new function (he usually called it theta(t)) using the same form as the solution to the associated homogeneous equation but with initial conditions such that, for t = 0, theta of t, theta prime of t, theta double prime of t, etc., all equaled 0, except for the final condition (theta^(n-1)(t)) which equaled 1.

## DIfficulty with outputting answers using ; and :...

I have a large program I have been writing using Maple 10 classic. The heart of the prgram is a large iterative loop that spits out various data as it converges on a solution. My problem is that I would like to see certain data and suppress other output. I accordingly assign a colon and semi-colon to the respective lines. But wether Maple actually displays what I want of not seems random. The screen is flooded with unwanted interim data, and only select desired output gets through. Is there some rule with what Maple outputs if its in an iterative or nested iterative loop?

## Problem with SparseIterative?...

Hello, everyone! I have a very nice, very sparse linear system (only containing 1s and -1s, with at most 2 entries per column). Thus, I immediately thought to take advantage the SparseIterative (or SparseDirect) methods associated with LinearAlgebra,LinearSolve, but alas, it isn't quite working. This is what I loosely do: gen_linear_system := proc(... some parameters ...) ... ls_m := Matrix(len, total_var, datatype='integer[1]', storage='sparse'); ... (fill matrix with appropriate 1s and -1s) return ls_m; end proc; solve_linear_system := proc(system_matrix::Matrix)

## fourier series...

hi! I want to do maplet application that fourier series calculate given funtions how do I? thank you...

Thanks

## How to plot the intersect line of two implicit fun...

Hi, Folks: I have two implicit functions (hyperboloid)： sqrt((x-28)^2+(y-2)^2+(z-2)^2)-sqrt((x-20)^2+(y+20)^2+(z-6)^2) = 2 sqrt((x+15)^2+(y-2)^2+(z-2)^2)-sqrt((x-20)^2+(y+20)^2+(z-6)^2) = 10 I am able to plot these two functions through display3d, but right now I want to plot the intersection line. Anybody has comments or suggestions? Thanks a lot, James

## first derivative...

Hi, How do i make maple to write a fist derivative with respect to time ie i want maple to show y' in the output.

## 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.