What is the angle `phi` between ` veca = 3.0 hati - 4.0 hatj and vecb =-2.0hati+ 3.0hatk`?

Explanation

To find the angle \( \phi \) between the vectors \( \vec{a} = 3.0 \hat{i} - 4.0 \hat{j} \) and \( \vec{b} = -2.0 \hat{i} + 3.0 \hat{k} \), we can use the dot product formula:

\[ \vec{a} \cdot \vec{b} = |\vec{a}| |\vec{b}| \cos \phi \]

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

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