Give an example for which `vecA.vecB=vecC.vecB` but `vecA!=vecC`.

Explanation

To solve the problem where we need to find an example such that \( \vec{A} \cdot \vec{B} = \vec{C} \cdot \vec{B} \) but \( \vec{A} \neq \vec{C} \), we can follow these steps:

### Step 1: Understand the Dot Product
The dot product of two vectors \( \vec{A} \) and \( \vec{B} \) is given by:
\[ \vec{A} \cdot \vec{B} = |\vec{A}| |\vec{B}| \cos \theta \]
where \( \theta \) is the angle between the two vectors.
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