Subject: solve(...) and unnecessary complex results
From: maxima-list at ssteiner.com
Date: Wed, 20 Feb 2008 22:32:55 +0100 (MET)
Dear Maxima experts,
If I make Maxima solve the following example equation it returns results which contain complex parts (%i) but I think the results should be "normal" real numbers.
Example: solve( (0=x^3-4*x+2), x );
Maxima returns:
[x = (-sqrt(3)*%i/2-1/2)*(3^-(3/2)*sqrt(37)*%i-1)^(1/3)+4*(sqrt(3)*%i/2-\
1/2)/(3*(3^-(3/2)*sqrt(37)*%i-1)^(1/3)),x = (sqrt(3)*%i/2-1/2)*(3^-(3/2)*sqrt(\
37)*%i-1)^(1/3)+4*(-sqrt(3)*%i/2-1/2)/(3*(3^-(3/2)*sqrt(37)*%i-1)^(1/3)),x = (\
3^-(3/2)*sqrt(37)*%i-1)^(1/3)+4/(3*(3^-(3/2)*sqrt(37)*%i-1)^(1/3))]
I think the correct results are -2,214; 0,539; 1,675
How to make Maxima return these results (real numbers) instead of complicated terms containing complex numbers?
Thank you!
Sebastian