The function is increasing when, if xa > xb, then f(xa) > f(b).
Let's choose values for x < 0 and for x > 0.
First, let's compare x = -2 and x = -1
-1 > -2
f(-1) < f(-2)
Then, the function is decreasing for x < 0.
Second, let's compare x = 1 and x = 2.
2 > 1
f(2) > f(1)
Then, the function is increasing for x > 0.
Answer: c. The function is increasing when x >0.
