Question

There are at least two ways of describing the set {7,8,...} is it true or false with short proof or a counterexample

Answer 1

Yes, there are atleast two ways of describing the set {7,8,...}.

A set can be described in two ways.

I) Roster form( Tabular form)

II) Set-Builder form (Rule method)

Usually a set is denoted in capital letters and the elements in it are denoted with small letters.

I)Roaster form: In this method a list of the elements in the set is being made.

Ex. For the above set, it can be expressed as

A={7,8,...}

II) Set builder form: Here an element X is provided with necessary conditions.

This method is used to simplify the set notations.

ex. For the above set, The set builder form will be,

A={X| where X>7}