Question 46
Let $A$ be the set of positive integers that can be written in the form $2x^2 + 3y^2$ where $x, y$ are integers with $x^2 + y^2 \neq 0$. Prove that:
a) All numbers from $A$ are not perfect square.
b) The product of an odd number of numbers from $A$ is not a perfect square.
a) All numbers from $A$ are not perfect square.
b) The product of an odd number of numbers from $A$ is not a perfect square.