Practice problem
Let f:{1,2,3}→{a,b,c}f:\{1,2,3\} \to \{a,b,c\}f:{1,2,3}→{a,b,c}. Which of the following definitions of fff have a function inverse?
f(1)=af(1) = af(1)=a, f(2)=bf(2) = bf(2)=b, f(3)=af(3) = af(3)=a
f(1)=cf(1) = cf(1)=c, f(2)=af(2) = af(2)=a, f(3)=bf(3) = bf(3)=b
f(1)=cf(1) = cf(1)=c, f(2)=cf(2) = cf(2)=c, f(3)=cf(3) = cf(3)=c
f(1)=bf(1) = bf(1)=b, f(2)=af(2) = af(2)=a, f(3)=cf(3) = cf(3)=c
f(1)=af(1) = af(1)=a, f(2)=af(2) = af(2)=a, f(3)=cf(3) = cf(3)=c
Type a concept, like “slope” or “photosynthesis”.