Find the direction cosines of the vector joining the points `A(1, 2, 3)`and`B(1, 2, 1)`, directed from A to B.

Explanation

To find the direction cosines of the vector joining the points \( A(1, 2, 3) \) and \( B(1, 2, 1) \), directed from \( A \) to \( B \), we can follow these steps:

### Step 1: Determine the coordinates of points A and B
The coordinates of point \( A \) are \( (1, 2, 3) \) and the coordinates of point \( B \) are \( (1, 2, 1) \).

### Step 2: Find the vector \( \overrightarrow{AB} \)
The vector \( \overrightarrow{AB} \) can be calculated using the formula:
\[
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