Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Somewhat disappointingly, Maxima seems not to be able to solve the following equation: solve(sqrt((x-a*e)^2+y^2)+sqrt((x+a*e)^2+y^2)=0,y); Even a TI89 can! Yours, Poul Riis