Which of the following are pairs of equal sets?
G = {–1, 1} and H = {x : x ϵ Z, x2 – 1 = 0}.
Equal Sets = Two sets A and B are said to be equal if they have exactly the same elements & we write A = B
We have,
G = {-1, 1}
and H = {x : x ϵ Z, x2 – 1 = 0}
Here, x ∈ Z and x2 – 1 = 0
The given equation can be solved as:
x2 – 1 = 0
⇒ x2 = 1
⇒ x = √1
⇒ x = ± 1
∴ x = -1 and 1
∴ H = {-1, 1}
⇒ G = H because elements of both the sets are equal.