CBSE 2026 · Region 2 · Set 1 · Q19 · 1 mark

For two vectors $\displaystyle \overrightarrow{\mathrm{a}}$ and $\displaystyle \overrightarrow{\mathrm{b}}$ Assertion (A) : $\displaystyle |\overrightarrow{\mathrm{a}} \times \overrightarrow{\mathrm{b}}|^{2}+(\overrightarrow{\mathrm{a}} \cdot \overrightarrow{\mathrm{b}})^{2}=|\overrightarrow{\mathrm{a}}|^{2}|\overrightarrow{\mathrm{b}}|^{2}$ Reason (R) : $\displaystyle |\overrightarrow{\mathrm{a}} \times \overrightarrow{\mathrm{b}}|=(\overrightarrow{\mathrm{a}} \cdot \overrightarrow{\mathrm{b}}) \tan \theta,\left(\theta \neq \frac{\pi}{2}\right)$

CBSE Class 12 Mathematics past-paper question from the 2026board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.