What is the unit vector in the direction of $3\hat{i} - 4\hat{k}$?

Explanation

1. 01

   $\lvert 3\hat{i} - 4\hat{k} \rvert = \sqrt{9 + 16} = 5$.

2. 02

   Divide by 5: $\frac{1}{5}(3\hat{i} - 4\hat{k})$.