<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>That doesn't answer Todd's question. But this does: </div><div><br></div><div><a href="http://www.wolframalpha.com/share/clip?f=d41d8cd98f00b204e9800998ecf8427efsfdt6pkjg">http://www.wolframalpha.com/share/clip?f=d41d8cd98f00b204e9800998ecf8427efsfdt6pkjg</a></div><div><br></div><div><br></div><br><div><div>On Aug 7, 2012, at 6:45 PM, Ray Racine wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Wolfram<div><br></div><div><a href="http://www.wolframalpha.com/input/?i=roots+x%5E2+%2B+2*x+%2B+10">http://www.wolframalpha.com/input/?i=roots+x%5E2+%2B+2*x+%2B+10</a></div><div><br><br><div class="gmail_quote">On Tue, Aug 7, 2012 at 6:28 PM, Matthias Felleisen <span dir="ltr"><<a href="mailto:matthias@ccs.neu.edu" target="_blank">matthias@ccs.neu.edu</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br> If it weren't against math conventions, I wouldn't mind seeing 1-i1 or 1/2+i2/3. But I am sure the people who produce Racket or Scheme or Lisp readers would hate me for that one, too. I think your students will need to cope, like all people who study sophisticated concepts (such as complex).<br> <br> Anyone know how Mathematica copes?<br> <div class="HOEnZb"><div class="h5"><br> <br> On Aug 6, 2012, at 6:05 PM, Todd O'Bryan wrote:<br> <br> > I just discovered that the way you enter (and display) a number like<br> ><br> > 1/2 + (2/3)i<br> ><br> > in Racket (and Scheme, presumably) is 1/2+2/3i.<br> ><br> > I understand why that is, and can't think of what else to do, but has<br> > anyone had students get confused because the form looks like the i is<br> > in the denominator of the imaginary part?<br> ><br> > What's more potentially confusing is that 1/2+2i/3 is a legal<br> > identifier in its own right.<br> ><br> > I'm working on a program that models basic algebra in the way that<br> > high school students are taught to do it, and one of my self-imposed<br> > rules has been that "math should look like math." In other words, I'm<br> > trying to minimize the conversion gymnastics that students have to put<br> > up with when they enter math in calculators or computer programs. In<br> > that spirit, I'm not sure if it would be better to allow the<br> > inconsistency with the way order of operations normally works or just<br> > have students enter 1/2+(2/3)i (or 1/2+2i/3, maybe) and do the<br> > conversion behind the scenes.<br> ><br> > Anyone have any thoughts or prejudices one way or the other?<br> ><br> > Todd<br> > ____________________<br> >  Racket Users list:<br> >  <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a><br> <br> </div></div><br>____________________<br>   Racket Users list:<br>   <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a><br> <br></blockquote></div><br></div> </blockquote></div><br></body></html>