Answer
(a) even
(b) odd
(c) even
(d) neither
(e) odd
(f) even
Work Step by Step
(a) f(-x) = (-x)² = x² = f(x) -> even
(b) f(-x) = (-x³) = -x³ = -f(x) -> odd
(c) f(-x) = |-x| = |x| = f(x) -> even
(d) f(-x) = -x + 1 $\ne$ f(x) $\ne$ -f(x) -> neither
(e) f(-x) = [-$x^{5}$ - (-x)]/[1 + (-x)²] = (-$x^{5}$ + x)/(1 + x²) = -f(x) -> odd
(f) f(-x) = 2 = f(x) -> even
