If \(A=\{1,4,9\}\) and the function \(f(x)=\sqrt{x}\), what is \(f(A)\)?

Correct answer: \(\{1,2,3\}\)

The set \(f(A)\) contains the function values of every element of \(A\). Here, \(f(1)=\sqrt{1}=1\), \(f(4)=\sqrt{4}=2\), and \(f(9)=\sqrt{9}=3\), so \(f(A)=\{1,2,3\}\). Option B is only the original set \(A\), not its image under the function. Exam tip: To find \(f(A)\), apply the function separately to each element of \(A\).