D = {x : x is an integer, x^2 ≤ 9}.

Question

Write the following sets in roster from: 

D = {x : x is an integer, x² ≤ 9}.

Answer 1

Integers = …, -4, -3, -2, -1, 0, 1, 2, 3, 4, … 

x = -4, x² = (-4)² = 16 > 9 

x = -3, x² = (-3)² = 9 

x = -2, x² = (-2)² = 4 

x = -1, x² = (-1)² = 1 x = 0, 

x² = (0)² = 0

x = 1, x² = (1)² = 1 

x = 2, x² = (2)² = 4 

x = 3, x² = (3)² = 9 

x = 4, x² = (4)² = 16 

The elements of this set are -3, -2, -1, 0, 1, 2, 3 

So, D = {-3, -2, -1, 0, 1, 2, 3}