Message Boards Message Boards

GROUPS:

Store variables after using Solve?

Posted 1 month ago
273 Views
|
4 Replies
|
4 Total Likes
|

Hello everyone, I'm new here and new to Mathematica, very excited about it.

I have two questions:

1)is there a way to store variables after a Solve operation? For example a=Solve[x+1==0,x]

2)solving this gives me troubles: Solve[s^2+s+1==0,s] result s -> -(-1)1/3}, {s -> (-1)2/3}. Correct result are two complex conjugate radixes, is that a sort of module+phase writing? If so is there a way to obtain arithmetic format? Using the domain field Solve[s^2+s+1==0,s,Complexes] doesn't help. The thing I do not understand further is that if I solve as^2 +bs +c==0 it gives be the classical 2nd order formula and if then I substitute a=b=c=1 then I get the correct complex radixes in arithmetic form!

Thanks.

4 Replies

Mathematica understands that the solution is complex and is probably trying to write it in the most compact form. To expand, you could use ExpToTrig like so

roots = (s /. Solve[s^2 + s + 1 == 0, s]) // ExpToTrig
ListPlot[(Tooltip[{Re[#1], Im[#1]}] &) /@ roots, AspectRatio -> 1]

You replied to everything in two lines, great, thanks a lot!

Posted 1 month ago

To answer your first question, if this is what you mean, try this.

Clear[a, b, c]; p = 
 Solve[{a^2 + b^2 == c^2, a > 0, b > 0, c > 0, a < b, c <= 50}, {a, b,
    c}, Integers]

and to then store the results, I use this method though there are other ways to achieve this.

q = {a, b, c} /. p

Hope this helps.

It's not what a really meant on 1) but thanks for reply. The different sintax you provided will be usefull in the near future.

Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Reply Preview
Attachments
Remove
or Discard

Group Abstract Group Abstract