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IKMC 2013 - Grades 11-12 - Paper 02 - Self-study Question 14

IKMC · IKMC 2013 - Grades 11-12 - Paper 02 - Self-study

Question 14

For a function on the integers, consider: “For every even x, f(x) is even.” What is its negation? Editorial note: printed option D omits the condition “x is even”. For this self-study item D is scored only with that explicitly restored condition; all printed choices below are preserved.
  1. For every even x, f(x) is odd.
  2. For every odd x, f(x) is even.
  3. For every odd x, f(x) is odd.
  4. There exists a number x for which f(x) is odd.
  5. There exists an odd x with f(x) odd.