How do you find a unit vector in the direction of 3i+4j-k?

1 Answer
Sep 18, 2016

(3 i + 4 j - k) / (sqrt(26))

Explanation:

We have: 3 i + 4 j - k

Let u = 3 i + 4 j - k.

Unit vectors are of the form hat(u) = (u) / (abs(u)):

=> hat(u) = (3 i + 4 j - k) / (abs(3 i + 4 j - k))

=> hat(u) = (3 i + 4 j - k) / (sqrt(3^(2) + 4^(2) + (- 1)^(2)))

=> hat(u) = (3 i + 4 j - k) / (sqrt(9 + 16 + 1))

=> hat(u) = (3 i + 4 j - k) / (sqrt(26))