23: D( f ) = (−∞,0) ∪ (0,∞); f is continuous there.
y-intercept: f (0) not possible; x-intercepts: f = 0 gives x equal to minus cubic root of 2.
f is not symmetric, see f = 0.
Limits at endpoints:

Interpretation as asymptotes:
No horizontal asymptote at −∞, but a chance for oblique.

So no oblique there.
Vertical asymptote at x = 0.
No horizontal asymptote at ∞, but a chance for oblique.

So no oblique there.

Now determine monotonicity using f ′.

Next hint
Answer