Find the angle between the vectors:
`vecA=hati-2hatj-5hatkandvecB=2hati+hatj-4hatk`

Explanation

To find the angle between the vectors \(\vec{A} = \hat{i} - 2\hat{j} - 5\hat{k}\) and \(\vec{B} = 2\hat{i} + \hat{j} - 4\hat{k}\), we can use the formula for the dot product of two vectors:

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

where \(\theta\) is the angle between the vectors.

...