15: The condition 2x − 4 ≠ 0 gives the domain

D( f ) = (−∞,2) ∪ (2,∞).

Now it is time to find limits at −∞, at 2 from the left and from the right, and at ∞.

Hint on limit at −∞
Hint on limit at 2 from the left
Hint on limit at 2 from the right
Hint on limit at ∞
Answer