a Let R R be the subspace of positive reals Show that R is
(a) Let R+ ? R be the subspace of positive reals. Show that R is homeomorphic to R+ .
(b) Show that (a,b) is homeomorphic to (0,1) .
(b) Show that (a,b) is homeomorphic to (0,1) .
Solution
a) f(x)=ex is continuous from R to R+ and has continuous inverse f-1(x)=ln(x)
b) f(x)=(x-a)/(b-a) is continuous from (a,b) to (0,1) and has continuous inverse f-1(x)=a+(b-a)x
It also works for part c)
