Question

List the members of these sets.

a) {x | x is a real number such that x 2 = 1}

b) {x | x is a positive integer less than 12}

Answer 1

Solution (a)

Given that

$Set\ A=\left \{ x | x \text \ is\ a\ real\ number\ such\ that\ x^2 = 1 \right \}$

solving

$x^2=1$

$x=\pm1$

Hence the given set in the tabular form will be

$Set\ A=\left \{ 1, -1\right \}$

Solution (b)

Given that

$Set\ B=\left \{ x | x\ is\ a\ positive\ integer\ less\ than\ 12 \right \}$

Clearly we know the positive integers less than 12 are $1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11$

Therefore, the given set in the tabular form will be

$Set\ B=\left \{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11\right \}$