solving system of equations [newbie]

On Wed, 2011-05-18 at 16:30 +0200, Hugo Coolens wrote:
> What is wrong with following sequence of commands?
> 
> eq1:x1=(-b+sqrt(b^2-4*c))/2;
> eq2:x2=(-b-sqrt(b^2-4*c))/2;
> solut:solve([eq1,eq2],[b,c]);
> 
> I expected to see b=-(x1+x2)/2 ... but I just get []
Hi Hugo,
you mean b = - (x1+x2)
I got the correct answer using a dirty hack:


(%i7) solut:solve([eq1+eq2,eq1*eq2],[b,c]);
(%o7) [[b = -x2-x1,c = x1*x2]]

Cheers,
Jaime