From help-request at octave dot org Mon Feb  7 01:04:43 2005
Subject: Re: two quadratic eq, please help
From: "Paul Thomas" <paulthomas2 at wanadoo dot fr>
To: "shih lin" <shlinlin at 37 dot com>
Cc: <help at octave dot org>
Date: Mon, 7 Feb 2005 08:09:00 +0100


>>   highly appreciate anyone can tell me how (or hint) to use octave to
>> solve:(12-x)^2 + y^2 =15^2, (16+y)^2+x^2=25^2 (by programming or using 
>> its built
>> in function)?

Are these to be solved simultaneously?  If so, there are two real solutions 
possible (ie both intersections of the two circles);

>From (i)   y = +/- ( 15^2 - (12-x)^2 ) ^0.5
 =>    (ii) (16 +/- ( 15^2 - (12-x)^2 )^0.5 )^2 + x^2 = 25^2

Then solve both of these roots with fsolve.

Paul T





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