Question: (a) Show that the point (0, 0) is an accumulation point of \({{\mathbb{R}}^{2}}\backslash \left\{ \left( 0,y \right)|y\in \mathbb{R} \right\}\)

(b) Show using definition of limit that limit of a function \({{\mathbb{R}}^{2}}\backslash \left\{ \left( 0,y \right)|y\in \mathbb{R} \right\}\mapsto \mathbb{R}\)

does not exist at (0, 0).