Question

D = {x : x is an integer, x^2 <_ 9}​

Answer 1

Answer:

$C = {x: x is an integer; x2 ≤ 4}. It can be seen that. (–1)2 = 1 ≤ 4; (–2)2 = 4 ≤ 4; (–3)2 = 9 > 4. 02 = 0 ≤ 4. 12 = 1 ≤ 4. 22 = 4 ≤ 4. 32 = 9 > 4. ∴C = {–2, –1, 0, 1, 2}$