If r = i + 2j and n = -i + 3j, find |2n – r|.
- 3.6
- 4.0
-
5.0
- 8.5
The correct answer is: C
Explanation
Given that, r = i + 2j and n = -i + 3j, to find |2n - r|
2n = 2(- i + 3j) = - 2i + 6j
2n - r = [- 2i + 6j] - [ i + 2j] = -3i + 4j
|2n - r| = |-3i + 4j| = \(\sqrt{(-3)^2 + 4^2}\) = \(\sqrt{9 + 16}\) = \(\sqrt{25}\) = 5.0