Let $K$ be the field of all algebraic numbers. Then does there exist an algebraically independent set of numbers $\pi_1, \dots, \pi_n$ such that $\Bbb{R} = K(\pi_1, \dots, \pi_n)$?
I don't know where to begin on this one or if it's even possible with my limited tools to solve it. Any ideas?
One thing I know is that if $r \notin L = K(\pi_1, \dots, \pi_n)$, then the minimal polynomial of $r$ over $K$ must have at least one transcendental coefficient.
Show that if $K$ is a countable field, then any finitely generated extension $K(x_1,\dots,x_n)$ is also countable.
One way to do this is to first show that the ring $K[x_1,\dots,x_n]$ is countable, and then use the fact that $K(x_1,\dots,x_n)$ is the fraction field of $K[x_1,\dots,x_n]$.