Week 9 discussion questions

1) Let f be a function on the set of integers defined by f(x) = 2xx + 10. Is f ‘onto’? Show your reasoning. (See E&C p 286; Tut. Letter 102, p 130 & examples in paragraph 4.6.3.)

2) Does the definition of a reflexive relation on page 302 in E&C say that one is required to prove that x = y? (The answer is no – explain!)

3) It must be proved that a relation is transitive. Describe how the proof must be developed.