Calculus
[4,∞)\left\lbrack4,\infty\right)
(−∞,−4] and [4,∞)\left(-\infty,-4\right\rbrack\text{ and }\left\lbrack4,\infty\right)
(−∞,−4] and [−4,∞)\left(-\infty,-4\right\rbrack\text{ and }\left\lbrack-4,\infty\right)
(−∞,4] and [4,∞)\left(-\infty,4\right\rbrack\text{ and }\left\lbrack4,\infty\right)