Find the domain of the function: f(x) = ^{x2 + 4x + 1}/_{x² - 3x + 2}

The denominator x² - 3x + 2 should not be equal to 0.

x² - 3x + 2 = 0

⇒ (x - 1)(x - 2) = 0

⇒ x = 1, 2

∴ Domain of f(x) = {x | x ∈ R, x ≠ 1, x ≠ 2}