1 | initial version |
Here is an illustration of getting radical expressions for the eigenvalues.
sage: A = matrix([[1, 1, 2], [1, -2, 0], [2, 0, 1]])
sage: a, b, c = A.eigenvalues()
sage: a, b, c
(-2.439311671683875?, -0.6611203141265045?, 3.100431985810380?)
sage: a.radical_expression()
-1/2*(1/18*I*sqrt(1373)*sqrt(3) + 5/2)^(1/3)*(-I*sqrt(3) + 1) + 1/3*(-4*I*sqrt(3) - 4)/(1/18*I*sqrt(1373)*sqrt(3) + 5/2)^(1/3)
Note that they are not nice radical expressions.