Answer
The magnitude is 1
Work Step by Step
In the previous part of this question (50e) we found
$d1 \times d2 = 0i + 0j -1k$
the magnitude of k is 1 because this is the only direction component for the solution of $d1 \times d2$
We can also calculate it:
magnitude $= \frac{vector}{unit_{ vector}}= \frac{-1k}{-1k} = 1 $
