Discrete Math question

Discrete Math question

Suppose A is the set of students currently registered at the University of Calgary, B is the set of professors at the University of Calgary, and C is the set of courses currently being offered at the University of Calgary. Under what conditions is each of the following a function. Explain your answers.

(a) {(a, b) | a is taking a course from b}

(b) {(a, c) | a’s first class each week is in c}

(c) {(a, c) | a has a class in c on Friday afternoon}