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Assume f: A B and g: B C are functions. Which are defined? (1) f g (2) g f (3) both (4) neither. Assume f: A B and g: B C are functions. What is the domain of g f ? A (2) B (3) C (4) f (5) g
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Assume f: A B and g: B C are functions. Which are defined? (1) f g (2) g f (3) both (4) neither
Assume f: A B and g: B C are functions. • What is the domain of g f ? • A (2) B (3) C (4) f (5) g • B A (7) B C (8) f g (9) g f • (10 or 0) A B
Assume f: A B and g: B C are functions. • What is the codomain of g f ? • A (2) B (3) C (4) f (5) g • B A (7) B C (8) f g (9) g f • (10 or 0) A B
What is the next line of this proof? • Let a A. • Let (x,y) A. • Let a g f. • Let (x,y) g f. • Let a Dom(g f). • Let (x,y) Dom(g f).
What is the next line of this proof? • Then a Dom(f). (2) Then (a, b) Dom(f) • (3) Then a g f. (4) Then (a,b) g f. • Then a Dom(g f). (6) Then (a,b) Dom(g f). • Then a f. (8) Then (a,b) f • (9) Then (a,b) A. (10) Then f(a) = b.