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 ′.

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