Let even function f (x) = log (a) | X-B | monotonically increase on (- infinite, 0), then the size relation between F (B + 2) and f (a + 1)? Why B = 0

Let even function f (x) = log (a) | X-B | monotonically increase on (- infinite, 0), then the size relation between F (B + 2) and f (a + 1)? Why B = 0

f(b+2)|x-b|=|-x-b|--->b=0
If f (x) = log (a) | x | (- infinite, 0), monotonically increasing - - > x > 0, monotonically decreasing - - > 0A + 1
--->f(b+2)