Path: news.mathworks.com!not-for-mail
From: "Narasimha Aditya " <ngollapu@asu.edu>
Newsgroups: comp.soft-sys.matlab
Subject: Non linear inequalities with 2 variables
Date: Sat, 24 Nov 2012 20:48:08 +0000 (UTC)
Organization: Arizona State University
Lines: 19
Message-ID: <k8rbq8$1nd$1@newscl01ah.mathworks.com>
Reply-To: "Narasimha Aditya " <ngollapu@asu.edu>
NNTP-Posting-Host: www-00-blr.mathworks.com
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Trace: newscl01ah.mathworks.com 1353790088 1773 172.30.248.45 (24 Nov 2012 20:48:08 GMT)
X-Complaints-To: news@mathworks.com
NNTP-Posting-Date: Sat, 24 Nov 2012 20:48:08 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 3873485
Xref: news.mathworks.com comp.soft-sys.matlab:783414

Hello All,

Is there a way to get the possible range for variables with help of a set of non linear inequalities? As in

I have a set like :

a1*x^2+b1*y^2+c1*x+d1*y+e1<0
a2*x^2+b2*y^2+c2*x+d2*y+e2<0
a3*x^2+b3*y^2+c3*x+d3*y+e3<0
0<=x<=1
0<=y<=1

Using set of above inequalities, can we get a possible range of x,y assuming all the constants are known above

I was able to get the range of x using one inequality using below : 

solution=feval(symengine, 'solve', 'x ^2*x+1>0','x', 'Real');

How to add set of equations above? And how to add another variable above?