Answer:
see explanation
Step-by-step explanation:
The denominator of f(x) cannot be zero as this would make f(x) undefined. Equating the denominator to zero and solving gives the values that x cannot be.
x² - 4 = 0 ⇒ x² = 4 ⇒ x = ± 2 ← excluded values
domain : x ∈ R, x ≠ ± 2
