Group Abstract Group Abstract

Message Boards Message Boards

Not a quantified system of equations and inequalities

Patrick Richardsen
Posted 4 years ago

Can someone please help me why I'm recieving this error. I am very new to Mathematica (just started yesterday), but I can do the calculation by hand why can't mathematica? I'm trying to solve the two equations R1 and R2 for P1 and P2. Maybe I'm just being dumb lol. Here is a screen dump: enter image description here
POSTED BY: Patrick Richardsen
3 Replies
Sort By:
Rohit Namjoshi
Rohit Namjoshi
Posted 4 years ago

Please post code that can be copied/pasted and evaluated to reproduce the problem.

Check the documentation for Solve. There are too many { }. Perhaps you mean this?

Solve[{R1 == (A + b c + k P2)/(2 b), R2 == m P1}, {P1, P2}]
(* {{P1 -> R2/m, P2 -> (-A - b c + 2 b R1)/k}} *)
POSTED BY: Rohit Namjoshi

Hi, i kinda figured it out. I think my code is pretty bad though. I will attach my Notebook, maybe you can come with some helpful tips. I further want to plug in values for my constants in order to graph my spesific problem, but do not know how to do this without ruining my general solution for the model.
POSTED BY: Patrick Richardsen
Rohit Namjoshi
Rohit Namjoshi
Posted 4 years ago

Something like this with some specific values for A, c1, b, k and varying m. The specific values are scoped to the With.

With[{vals = {A -> 1, c1 -> 2, b -> 1, k -> 1}},
 eqns = {P1, P2} /. First@Eq /. vals;
 Plot[eqns, {m, 0, 1}, PlotLegends -> "Expressions"]]

enter image description here
POSTED BY: Rohit Namjoshi
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Tag limit exceeded
Note: Only the first five people you tag will receive an email notification; the other tagged names will appear as links to their profiles.
Reply Preview
Attachments
Remove
or Discard