Assignment:
Show the Galois group of (x^2-2)(x^2+2) over Q (rationals) is isomorphic to Z_2xZ_2 (Direct product group of integers modulo 2).
For your choice of your mapping theta, that is operation preserving, 1 to 1, and onto please show that is well defined.
Provide complete and step by step solution for the question and show calculations and use formulas.