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If $\vec a$ is a non-zero vector, then always |
$\vec a.\vec a=0$ $\vec a.\vec a>0$ $\vec a.\vec a<0$ $\vec a.\vec a=1$ |
$\vec a.\vec a>0$ |
The correct answer is Option (2) → $\vec a.\vec a>0$ Given: $\vec{a}$ is a non-zero vector. Then, $\vec{a} \cdot \vec{a} = |\vec{a}|^2$ Since $\vec{a} \ne \vec{0} \Rightarrow |\vec{a}| > 0 \Rightarrow |\vec{a}|^2 > 0$ ∴ $\vec{a} \cdot \vec{a} > 0$ |
