Show that  is neither increasing nor decreasing on R.
 is neither increasing nor decreasing on R.
We have,

Case 1
When x [0,
 [0, )
)
Let  >
> 
⇒ 
⇒ 
⇒ 
 f(x1) < f(x2)
f(x1) < f(x2)
⇒  f(x) is decreasing on[0,∞).
 f(x) is decreasing on[0,∞).
Case 2
When x (-
 (- ,0]
,0]
Let  >
> 
⇒ 
⇒ 
⇒ 
⇒ 
 f(x) is increasing on(-∞,0].
 f(x) is increasing on(-∞,0].
Thus, f(x) is neither increasing nor decreasing on R.