Find a unit vector perpendicular to both vectors
`vecA=3hati+4hatj and vecB=-3hati+7hatj`.

Explanation

To find a unit vector that is perpendicular to both vectors \(\vec{A} = 3\hat{i} + 4\hat{j}\) and \(\vec{B} = -3\hat{i} + 7\hat{j}\), we will use the cross product of the two vectors. Here’s a step-by-step solution:

### Step 1: Write down the vectors
We have:
\[ \vec{A} = 3\hat{i} + 4\hat{j} \]
\[
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