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>
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<br></blockquote></div><br></div>