If ` vec a\ a n d\ vec b` are unit vectors find the angle between ` vec a+ vec b\ a n d\ vec a- vec bdot`

Explanation

To find the angle between the vectors \( \vec{a} + \vec{b} \) and \( \vec{a} - \vec{b} \), we can use the formula for the cosine of the angle between two vectors, which is given by:

\[ \cos \theta = \frac{(\vec{a} + \vec{b}) \cdot (\vec{a} - \vec{b})}{\|\vec{a} + \vec{b}\| \|\vec{a} - \vec{b}\|} \]

### Step 1: Calculate the dot product \( (\vec{a} + \vec{b}) \cdot (\vec{a} - \vec{b}) \)

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