Hi,

I am trying to build a procedure to check to see if an nxn matrix is elementary. I am working with the standard definition of an elementary matrix, a square matrix that is formed by performing exactly one row operation on the corresponding identity matrix. It could also be interpreted as a matrix that is exactly one row operation from becoming the identity matrix. Does anyone have any idea how this might be done?

Thanks!

I have two simple implicitly defined curves: 0.5y^2-x-3 = 0 and x+y=1. I would like to plot these curves implicitly and shade the region enclosed by them. I've tried using the plots:-implicitplot( ) as shown, but I can't get just the enclosed region to be shaded. I know how to acheive this using the explicit equations. I am looking for an implicitplot solution, assuming there is one.
 

Download shade_implicitplot.mwshade_implicitplot.mw

I recently got a question answer regarding drawing a weighted digraph. That got me thinking about more "complicated" networks, i.e., electrical networks. Is it possible to draw the following electrical network in Maple? I know it can be done quite easily in MapleSim, but how about Maple?

I am trying to create the image shown below in Maple.

I am able to created the nodes and edges fairly easily. I would like to know how to add the labels to each edge, formatted as shown, and more importantly, have the edges decorated with the arrows, also as shown. I've tried playing around with digraphs, but I'm not really getting the desired look. I've attached my attempt and welcome any suggestions as to how to improve what I've done so far, as well as achieve my goal.

network.mw

I have intervals A=(-infinity,7), B=(-10,25), and C=(15,infinity). How do I use Maple to perform the union and intersection of such intervals?