20. Let function $f : R \rightarrow R$ be defined by $f ( x ) = 2 x + \sin x$ for $x \in R$ Then $f$ is (A) One-to-one and onto (B) One-to-one but NOT onto (C) Onto but NOT one-to-one (D) Neither one-to-one nor onto
20. Let function $f : R \rightarrow R$ be defined by $f ( x ) = 2 x + \sin x$ for $x \in R$ Then $f$ is\\
(A) One-to-one and onto\\
(B) One-to-one but NOT onto\\
(C) Onto but NOT one-to-one\\
(D) Neither one-to-one nor onto\\