If \(f:\{1,2,3,4\}\to\{1,2,3,4\}\) is defined by \(f(x)=x\) when \(x\) is odd and by \(f(x)=5-x\) when \(x\) is even, what is its range?

Correct answer: \(\{1,3\}\)

For the odd inputs, \(f(1)=1\) and \(f(3)=3\). For the even inputs, \(f(2)=5-2=3\) and \(f(4)=5-4=1\). Thus, the distinct output values are only \(1\) and \(3\), so the range is \(\{1,3\}\). Exam tip: the range contains the actual distinct outputs, not necessarily every element of the codomain.