Find the angle between the vectors `2hati-hatj+hatkand3hati+4hatj-hatk`.

Explanation

To find the angle between the vectors \( \mathbf{a} = 2\hat{i} - \hat{j} + \hat{k} \) and \( \mathbf{b} = 3\hat{i} + 4\hat{j} - \hat{k} \), we can use the formula for the cosine of the angle between two vectors:

\[ \cos \theta = \frac{\mathbf{a} \cdot \mathbf{b}}{|\mathbf{a}| |\mathbf{b}|} \]

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

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