Question

Show that the class of closed intervals [a,b] where a and b are rational and a

Answer 1

It is given below hope it helps.

Answer 2

Step-by-step explanation:

let a collection B={ [a, b] : a, b€Q, a<b}

1. clearly R=U[x-1, x]

x€R

2.Let [a-1, a] ,[a, a+1] be any two members of B.

and intersection between these two members is {a}

so for a€{a}, ther does not exist [c, d] €B such that

a€[c,d] subset of {a}

Hence B is not a base for any topology on R.