4: D( f ) = (−∞,0) ∪ (0,∞);f is continuous there.
y-intercept:f (0) not possible;
x-intercepts:f = 0 not possible.
f is not symmetric since f (−x) is not equal to
f (x) nor to -f (x) (try e.g.
x = 1).
Limits at endpoints:
Interpretation as asymptotes:
Horizontal asymptote y = 0 at
−∞.
Vertical asymptote at x = 0.
No horizontal asymptote at ∞, but a chance for oblique.
