The solution of the quadratic inequality (x3 + x – 12) ≥ 0 is
-
A.
x ≥ -3 or x ≤ 4 -
B.
x ≥ 3 or x ≥ -4 -
C.
x ≤ 3 or x v -4 -
D.
x ≥ 3 or x ≤ -4
Correct Answer: Option B
Explanation
(x3 + x – 12) ≥ 0
(x + 4)(x – 3) ≥ 0
Either x + 4 ≥ 0 implies x ≥ -4
Or x – 3 ≥ 0 implies x ≥ 3
∴ x ≥ 3 or x ≥ -4