Answer 1

{x : x ∈ Z and x² ≤ 4}

When x² = 4
x = ± `sqrt(4)` = ±2

When x² = 1
x = ± `sqrt(1)` = ±1

When x² = 0
x = `sqrt(0)` = 0

∴ Elements of the given set {x : x ∈ Z and x² ≤ 4} are +2, -2, +1, -1, 0 or are -2, -1, 0, 1, 2