Question

RESOUVA EM R :
$1 \leq x^{2} \leq 9$

Answer 1

                  1 ≤ x² ≤ 9
                  ↓    ↓     ↓
                 √1  √x²  √9
                  ↓    ↓     ↓
                  1    x     3

      S = {x ∈ R|| 1 ≤ x ≤ 3}