Let f (x) be an odd function on (- ∞, + ∞), f (x + 2) = - f (x). When 0 ≤ x ≤ 1, f (x) = x, then f (7.5) is equal to () A. 0.5B. -0.5C. 1.5D. -1.5

Let f (x) be an odd function on (- ∞, + ∞), f (x + 2) = - f (x). When 0 ≤ x ≤ 1, f (x) = x, then f (7.5) is equal to () A. 0.5B. -0.5C. 1.5D. -1.5

∵ f (x + 2) = - f (x), ∵ f (x) is an odd function on (- ∞, + ∞) ∵ f (- x) = - f (x). ∵ so f (7.5) = f (- 0.5) = - f (0.5) = - 0.5