CBSE 2025 · Region 5 · Set 1 · Q20 · 1 mark

Assertion (A) : Let $\displaystyle \mathrm{A}=\{\mathrm{x} \in \mathrm{R}:-1 \leq \mathrm{x} \leq 1\}$. If $\displaystyle \mathrm{f}: \mathrm{A} \rightarrow \mathrm{A}$ be defined as $\displaystyle \mathrm{f}(\mathrm{x})=\mathrm{x}^{2}$, then $\displaystyle \mathrm{f}$ is not an onto function. Reason $\displaystyle (\mathrm{R}): \quad$ If $\displaystyle \mathrm{y}=-1 \in \mathrm{~A}$, then $\displaystyle \mathrm{x}= \pm \sqrt{-1} \notin \mathrm{~A}$.

CBSE Class 12 Mathematics past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.