If $\vec a$ and $\vec b$ are two non-zero orthogonal vectors, then $|\vec a + \vec b|$ is equal to

$|\vec a-\vec b|$

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, $|\vec{a}+\vec{b}| = |\vec{a}-\vec{b}|$