Question

If $f:R\to R$ defined by $f\left(x\right)=x^2$ is

• A. one-one but not onto
• B. onto but not one-one
• C. bijective
• D. neither one-one nor onto

Answer 1

Answer: (D)

neither one-one nor onto

graph of $f\left(x\right)=x^2$ on R
$\because f\left(x\right)$ is not a monotonic function & its range is $(0,\infty )$.
$\therefore$ $f\left(x\right)$ is niether onto nor one - one.