17: D( f ) = ℝ;
f is continuous there.
y-intercept: f (0) = 0;
x-intercepts: f = 0 gives
x = 0.
f (−x) = −f (x),
hence f is odd.
Limits at endpoints:

Interpretation as asymptotes:
Horizontal asymptote y = 0 at
−∞.
Horizontal asymptote y = 0 at
∞ (this also follows by
symmetry).
Now determine monotonicity using f ′.
Next hint
Answer