If $\vec a$ and $\vec b$ are two non-zero orthogonal vectors, then $|\vec a + \vec b|$ is equal to
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $|\vec a-\vec b|$
Given: $\vec{a}$ and $\vec{b}$ are two non-zero orthogonal vectors.
$|\vec{a}+\vec{b}|^{2} = |\vec{a}|^{2} + |\vec{b}|^{2}$
$|\vec{a}-\vec{b}|^{2} = |\vec{a}|^{2} + |\vec{b}|^{2}$
Hence, $|\vec{a}+\vec{b}| = |\vec{a}-\vec{b}|$.
Therefore, $|\vec{a}+\vec{b}| = |\vec{a}-\vec{b}|$