Answer: -4 ≤ x ≤ 1
Step-by-step explanation:
A function f(x) is called increasing in an interval [a,b] when f'(x) > 0 in the interval (a,b).
That is, in that interval, with increasing the value of x the value of f(x) increases.
Let f(x) be the function which is shown in the given diagram.
Since, by the given diagram,
In the interval [tex](-\infty, -4)[/tex], f(x) decreases as x increases,
Hence In this interval given function is decreasing.
In the interval [-4, 1], f(x) increases as x increases,
Hence In this interval given function is increasing.
In the interval (1,6), f(x) is constant as x increases,
Hence In this interval given function is neither increasing nor decreasing.
In the interval [tex](6,\infty)[/tex], f(x) decreases as x increases,
Hence In this interval given function is decreasing.
