Question

Write the set $A=\{xϵz,x^2<20\}$ in the roster form

Answer 1

We observe that the squares of integers $0,\pm 1,\pm 2,\pm 3,\pm 4$ are less than 20. Therefore,the set A in roster form is $A=\{-4,-3,-2,-1,0,1,2,3,4\}$.