Let $f(x) = \dfrac{x^2}{x-1}$. Which of the following is true? (A) $f$ is neither one-one nor onto (B) $f$ is one-one and onto (C) $f$ is one-one but not onto (D) $f$ is onto but not one-one
$f'(x) = -2/(x-1)^2 < 0$, so $f$ is strictly decreasing, hence one-one and onto. (D)
Let $f(x) = \dfrac{x^2}{x-1}$. Which of the following is true?
(A) $f$ is neither one-one nor onto
(B) $f$ is one-one and onto
(C) $f$ is one-one but not onto
(D) $f$ is onto but not one-one