Let f: A->B and g: B->C(adsbygoogle = window.adsbygoogle || []).push({});

a. C_{0}[tex]\subset[/tex]C, show that (g o f)^{-1}(C_{0}))=f^{-1}(g^{-1}(C_{0})).

b. If f and g are injective, show that g o f is injective

c. If g o f is injective, what can you say abuot injectivity of f and g?

d. If f and g are surjective, show that g o f is surjective.

e. If g o f is surjective, what can you say about surjectivity of f and g.

f. Summarize your answers to (b)-(e) in the form of a theorem

I don't know how to do this.... can someone else me..?

Thank You

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# Injectivity vs. surjectivity

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