What are the properties fo two vectors `vec(a) and vec(b) ` such that `vec(a) + vec(b) = vec(a) - vec(b)` ?

Explanation

To solve the problem of finding the properties of two vectors \(\vec{a}\) and \(\vec{b}\) such that \(\vec{a} + \vec{b} = \vec{a} - \vec{b}\), we can follow these steps:

### Step 1: Set up the equation
We start with the given equation:
\[ \vec{a} + \vec{b} = \vec{a} - \vec{b} \]

...