Consider the function f(x) = x e 2 20x For this function there are three important intervals: ( - oo, A], [A, B], and [B, co) where A and B are the critical numbers. Find A and B For each of the following intervals, tell whether f() is increasing (type in INC) or decreasing (type in DEC). ( - 00, A]: [A, B] [B, 0.)