Question

If f: A→B and I_A is the identity function on A, which relation is correct?

Options

• \(f\circ I_A=f^{-1}\)

• \(f\circ I_A=0\)

• \(f\circ I_A=f\)

• \(f\circ I_A=I_A\)

Answer 1

An identity function leaves its input unchanged. Thus, applying \(I_A\) before \(f\) does not alter the result, giving \(f\circ I_A=f\).