Practicing Success
Practicing Success
CUET Preparation Today
| If \(\vec{a},\vec{b},\vec{c}\) are three unit vectors such that \(\vec{a}+\vec{b}+\vec{c}=0\) and \(m=\vec{a}\cdot \vec{b}+\vec{b}\cdot \vec{c}+\vec{c}\cdot \vec{a}\) then evaluate \(m\). |
m < 0
m > 0
m = 0
m = 3
|
| m < 0 |
| \(\begin{aligned}(\vec{a}+\vec{b}+\vec{c})^{2}&=0\\ |\vec{a}|^{2}+|\vec{b}|^{2}&+|\vec{c}|^{2}+2m=0\\ m&=-\frac{3}{2}<0\end{aligned}\) |
