CBSE 2024 · Region 3 · Set 3 · Q19 · 1 mark
Assertion (A) : For any non-zero unit vector $\displaystyle \overrightarrow{\mathrm{a}}, \overrightarrow{\mathrm{a}} \cdot(-\overrightarrow{\mathrm{a}})=(-\overrightarrow{\mathrm{a}}) \cdot \overrightarrow{\mathrm{a}}=-1$. Reason $\displaystyle (R)$ : Angle between $\displaystyle \overrightarrow{\mathrm{a}}$ and $\displaystyle (-\overrightarrow{\mathrm{a}})$ is $\displaystyle \frac{\pi}{2}$.
Official answer
From CBSE’s own marking scheme for this paper.
(C)
Assertion (A) is true, but Reason (R) is false.
Vector AlgebraProduct of Two VectorsAnalyseassertion_reasoneasy
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CBSE Class 12 Mathematics past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.