Question

a=(1,1/8,1/27,1/67,1/125) IN SET BUILDER FORM

Answer 1

First your question must contain 64 instead of 67.

Notation: x€A means x belongs to A

As you see, 1, 8, 27, 64 and 125 are perfect cubes.

So, set A can be written as:

A = {1/x^3 ; x€N, x≤5 }

Where N is the set of natural numbers.

Answer 2

Your question might be

A = {1,1/8,1/27,1/64,1/125}

(64 instead of 67)

It is in roaster form.

We need to change it to set builder form.

Let x be the numbers

x€A (x belongs to A)

N → Natural number.

Here,as we observe we find that the numbers are perfect cubes.

A = {x : 1/x³ is a perfect cube and x€N , x ≤ 5}

Hope it helps