Calculate the angle between the two vectors
`vecA=-2hati+hatj-3hatk and vecB =hati-2hatj+hatk`

Explanation

To calculate the angle between the two vectors \(\vec{A} = -2\hat{i} + \hat{j} - 3\hat{k}\) and \(\vec{B} = \hat{i} - 2\hat{j} + \hat{k}\), we can use the dot product formula. The formula for the angle \(\theta\) between two vectors is given by:

\[ \cos(\theta) = \frac{\vec{A} \cdot \vec{B}}{|\vec{A}| |\vec{B}|} \]

### Step 1: Calculate the dot product \(\vec{A} \cdot \vec{B}\)

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