z = (3.125,4.25)
 has real part = 3.125
 and imaginary part = 4.25i
z has complex conjugate = (3.125,-4.25)
AGM((3.125,4.25),(1,0)) = (2.0783161721733,1.5633615899066)

AGM((1,1),(2,1)) = (1.4713493628647,1.0200541263377)

Enter Integer coefficients of a (monic) cubic:The 1 root(s) are:
[ -1 ]
Enter a real or complex: Main cube root = (1.6289371459222,0.52017450230455)
whose cube is    (3,4)
Next cube root = (-1.2649529063578,1.1506136983845)
whose cube is    (3,4)
Next cube root = (-0.36398423956442,-1.670788200689)
whose cube is    (3,4)
Enter real coefficients a b c d e of a quartic:Quartic [1,2,3,4,5] has roots:
(-1.2878154795576,-0.85789675832849)
(-1.2878154795576,0.85789675832849)
(0.28781547955765,1.4160930801719)
(0.28781547955765,-1.4160930801719)