In: Advanced Math
Exercise We say that |A| = |B| if there exists a bijection f : A → B.
(a) Show that the intervals [1, 2] and [3, 7] have the same cardinality.
(b) Show that the intervals (0, 1) and (0, ∞) have the same cardinality. (Hint: First try (0, 1) and (1, ∞) (later subtract 1). Identify numbers small numbers in (0, 1) with large numbers in (1, ∞) somehow.)
(c) Show that the interval (0, 1) and the real numbers R have the same cardinality. (Hint: tan-1x.)