## Subscripts...

On subscripts. I like to use them as part of variable names but Maple does this to me.

Lets say I have

## Differential...

My question is about how Maple handles differentials.

In its derivation of an equation for pressure as a function of depth my physics text comes up with this:

from which it gets

## Text in 2D without the math...

How can I write with 2D math in text mode? That is, I want to create a document with mathematical expressions but I don't want Maple to do any mathematical operations on them. Imagine that you're trying to write a page in a textbook with expressions put in normal notation and interspersed with comments - that's what I'm trying to do. I've tried Text>Maple Input, Text>2D Input, Text>2D Math, Text>Normal, etc, etc but they all just put out 1D. And if I try to use "Math" instead it invariably does some sort of simplification or normalization or some such when I don't want it to touch the expressions I enter at all.

## Typesetting...

Hi, I have a question. I work with maple in a fairly unusual way. I use the vim editor and the command line interface (don't try to change this it won't help). Then I typeset my results using the latex mode. I am wondering of late if I can read my input into the graphical version of maple and control the formatted output produced by the gui. i.e. is there some analog of `latex/special_names`[x1] := `x_1` For the gui interface. I can't seem to find this documented anywhere. Thank you, Derek

## piecewise function...

Hi all I have a(x) and b(x), a(x) is only interesting from x=0..5 and b(x) from 5..10. How can I define those to into one c(x)? I guess I need the piecewise function, but I don't understand anything from the help file.. Can anyone please explain it to me, thanks.

## Graphing a moving point about a spehre...

i need to take a sphere and and graph a point going around the sphere. i have the code: restart: with(plots): with(plottools): x1:=(u,v)-> sin(u*Pi)*cos(v*Pi); y1:=(u,v)-> sin(u*Pi)*sin(v*Pi); z1:=(u,v)-> cos(u*Pi); x2:=(u,v)-> 3*sin(u*Pi)*cos(v*Pi); y2:=(u,v)-> 3*sin(u*Pi)*sin(v*Pi); z2:=(u,v)-> 3*cos(u*Pi); p1:=plot3d([x1(u,v), y1(u,v),z1(u,v)] ,u=0..1,v=0..2,color=blue, axes=normal): points:={seq([x1(k/50),y1(k/50),z1(k/50)], k=0..314 )}: display(p1); pointplot3d:(points); only i get the error Error, invalid input: x1 uses a 2nd argument, v, which is missing how do i put in arguments for u & v?

## Help in maple homework...

I had a new homework in maple but there is two questions that i have a hard time figuring them out. If somewone could help me it would be nice. 1. It says that E=L{v1,v2,v3,v4} (all vectors) where v1= (-5,3,2,0,1), v2=(0,-1,1,3,0), v3=(3,1,0,0,2) and v4=(1,4,4,2,0). Discribe E, which is a subset of R5 (and the teacher would like a description like this exemple: E={(x,y) ∈R2 ∣ 2x-3y=2} 2. A matrix: A := Matrix(5, 5, {(1, 1) = 1, (1, 2) = 0, (1, 3) = 0, (1, 4) = 0, (1, 5) = 0, (2, 1) = 0, (2, 2) = 4, (2, 3) = 0, (2, 4) = 0, (2, 5) = 0, (3, 1) = 0, (3, 2) = 0, (3, 3) = 52, (3, 4) = 0, (3, 5) = 0, (4, 1) = 0, (4, 2) = 0, (4, 3) = 0, (4, 4) = 7, (4, 5) = 0, (5, 1) = 0, (5, 2) = 0, (5, 3) = 0, (5, 4) = 0, (5, 5) = 3})

## expand...

how do i expand [ln(1+x)]^2??? and find partial derivatives of functions

## Plotting 3D opaque shapes from a file?...

I'm generating fairly complex shapes and dumping the x,y,z coordinates of each point to a text file. The shapes have a high degree of spherical symmetry, so they usually look like a torus or ellipsoid. I've been using pointplot3d to plot the shapes using 'style=line'. The result is something that looks close enough to a wireframe plot. However, for my final thesis I will be submitting, I'd like to show the shapes opaquely (with hidden lines). Basically, the type of plot generated by: plot3d(sin(phi)^2, theta=0..2*Pi, phi=0..Pi,coords=spherical,style=wireframeopaque,color=black);

## Integrating BSplineCurve in Maple 8...

Hello everybody, does anyone know how to integrate the output of BsplineCurve in maple 8? I can plot it over a given interval, but if I try to perform the corresponding definite integral, I get the following error message: Error, (in int) wrong number (or type) of arguments as opposed to the output of the Spline routine, which can be integrated without problems. Thank you for your help.

## algebraic curves...

Hi everybody, is there any Maple package to deal with algebraic curves? The problem I have to solve is the following: my thesis advisor gave me a polynomial equation in two variables, which I know it is a Riemann surface of genus 0. As far as I know, there is a theorem which says that this surface is birationally equivalent to an elliptic curve. There should be also an algorithm which receives the equation as input and outputs the rational parametrization of the Riemann surface. Moreover, this algorithm should be available in a Maple package (my advisor told me this... the problem is that he does not remember the name of the package, nor the function!!!).

## Zipping a Maple library...

I have a small Maple library (created with march and savelib) that I want to distribute to some people. It seems to work fine, but if I zip it (with the idea of mailing it), the resulting zipped directory under windows seems to throw up security warnings and gets rejected by my outgoing mail client for being "oversize" although it is in fact small. Are Maple libraries so created just standard files or are they special in some way? I'd be grateful for any insight. Toby