Last one:

(3):
(i) Show that $\displaystyle \mathbb{F}(x)/(x^2 -1) \cong \mathbb{F} \times \mathbb{F}$ when $\displaystyle \mathbb{F}$ is any field in which $\displaystyle 1 + 1 \neq 0 $.
(ii) Show that $\displaystyle \mathbb{R}(x)/(x^2 + a) \cong \mathbb{C}$ if a > 0, or $\displaystyle \mathbb{R} \times \mathbb{R}$ if a < 0.

any suggestions on these please? thnx