Find the direction cosines of the vector (4i – 3j).
-
A.
(frac{9}{10}, frac{27}{10}) -
B.
(frac{17}{27}, -frac{17}{27}) -
C.
(frac{4}{5}, -frac{3}{5}) -
D.
(frac{4}{7}, frac{-3}{7})
Correct Answer: Option C
Explanation
Given (V = xi +yj), the direction cosines are (frac{x}{|V|}, frac{y}{|V|}).
(|4i – 3j| = sqrt{4^{2} + (-3)^{2}} = sqrt{25} = 5)
Direction cosines = (frac{4}{5}, frac{-3}{5}).