Practicing Success
Practicing Success
CUET Preparation Today
Let O be the origin, and $\vec{OX}, \vec{OY},\vec{OZ}$ be three unit vectors in the directions of the sides $\vec{QR},\vec{RP},\vec{PQ}$ respectively, of a triangle PQR. Then, $|\vec{OX}×\vec{OY}|=$ |
$\sin (P+Q)$ $\sin 2R$ $\sin (P+R)$ $\sin (Q+R)$ |
$\sin (P+Q)$ |
$|\vec{OX}×\vec{OY}|$ $=|\vec{OX}||\vec{OY}|\sin (π-R)$ $=\sin R = \sin (π-(P+Q)) = \sin (P+Q)$ $[∵P+Q+R=π]$
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