Question

If $f:R \rightarrow R,$ then $f(x) = |x|$ is

• A. One-one but not onto
• B. Onto but not one-one
• C. One-one and onto
• D. None of these

Answer 1

Answer: (D)

None of these

Answer 2

$f( - 1) = f(1) = 1$ $\therefore$function is many-one function.

Obviously, f is not onto so f is neither one-one nor onto.