Consider the function ` f(x) = -7 (x - 4)^(2//3) `. For this function there are two important open intervals: ` (-\infty, A) ` and ` (A,\infty) ` where ` A ` is a critical number.
Find ` A `  

For each of the following intervals, tell whether ` f(x) ` is increasing or decreasing.
` (-\infty, A) `: Select an answer Increasing Decreasing
` (A,\infty) `: Select an answer Increasing Decreasing