Robert Israel: It came to me in a dream last night:

Im((diff(r(x)*exp(I*theta(x)), x))/(r(x)*exp(I*theta(x)))) = diff(theta(x), x);
<\pre>

At least it was in my head when I woke up this morning.

Do you find applications for this gem frequently?

Robert Israel: I don't know what you’re doing yet, but it works beautifully. With some help from help, I think that I'll figure it out in a while.

Robert Israel: I don't know what you’re doing yet, but it works beautifully. With some help from help, I think that I'll figure it out in a while.

This seems to do it: plot(180*`if`(argument(F(x)) < 0, argument(F(x))+2*Pi, argument(F(x)))/Pi, x = -.1 .. 2, axes = boxed); I'm sure there must be a better way. Something that always works not just in this case. Sure is fun talking to my self. P.S. F := proc (x) options operator, arrow; (1-x^2)^(3/2)-1 end proc;

This seems to do it: plot(180*`if`(argument(F(x)) < 0, argument(F(x))+2*Pi, argument(F(x)))/Pi, x = -.1 .. 2, axes = boxed); I'm sure there must be a better way. Something that always works not just in this case. Sure is fun talking to my self. P.S. F := proc (x) options operator, arrow; (1-x^2)^(3/2)-1 end proc;

J. Tarr: Thank you. The Introductory Programming Guide seems to be just what I need. I'm reading it. How long has this book been available? It's dated 2007.

Acer: Yes, that helps some. Thank you. I read every word and I'll read every word again. I appreciate your time and effort. I wish that there was as source of quality (unlike mine) Maple code that was available to read and learn from. I can follow what you did and apply your approach to other problems that are just a little different but I couldn't have come up with such a solution without your help of similar help. Thanks again.

Acer: I liked it. I've been trying to understand "a crude approach". The bit that I think I would be least likely to discover without your help is: "identical(B7)=anything". Help has something to say about "identical" and "anything" but "identical(B7)=" seems like it should be "identical(B7)||=". I would also expect some punctuation between "identical(B7)=" and "anything". It selects any expression that contains "B7=". Correct? "op" isn't doing what I would at first expect it to do. "select" yields a set with one element and "op" extracts that element, "B7 = 204+1024*Z1", rather than "B7, 204+1024*Z1", which is what I first expected. Is the "map(y->op(select(x->type(x,identical(B7)=anything),y)),{%}):" an idiom that's well known to those who know it well? Does one have to read a lot of stuff written in Maple to get it? Is there anything like "Software Tools" by Kernighan & Plauger (which was for C) for Maple? http://www.amazon.com/Software-Tools-Brian-W-Kernighan/dp/020103669X

Acer: Wow! What a performance. That's better than Circ De Sola for me. OK, number theory isn't your field. What is? Who are you? "If anyone wants to teach me some number theory here, that could be fun." Sorry, I fear that I will be no fun. How did you acquire your skills? How did you come to be who you are?

Acer: I think that that helped a lot. Thank you. Here is more of what I was looking for: View 4937_DiophantusPeter2.mw on MapleNet or Download 4937_DiophantusPeter2.mw
View file details I wanted to find the value 204, a value that makes all of the elements of X integers. 204 is the smallest, 1228 is the next, ... Is there a better way? People are so much more user-friendly than programs. Thank you again.

This is my first attempt to get help here so I don't know if I'm doing this right.