1.- Show that (R, τs) is connected. Also show that (a, b) is
connected, with the subspace topology given by τs.
2. Let f: X → Y continue. We say that f is open if it sends open
of X in open of Y. Show that the canonical projection
ρi: X1 × X2 → Xi
(x1, x2) −→ xi
It is continuous and open, for i = 1, 2, where (X1, τ1) and (X2,
τ2) are two topological spaces and...