Consider the function f(z) =6x+2z1. For this function there are four important intervals: (-co, A], [A, B),(B, C), and [C, oo) where A, and C are the critical numbers and the function is not defined at B. Find A and B and C For each of the following intervals, tell whether f(z) is increasing (type in INC) or decreasing (type in DEC). (-00, A]: [A, B): (B, C): [C,00)