Question

Find the angle between the given vectors to the nearest tenth of a degree.

u = 6, -1, v = 7, -4

20.3°
10.2°
0.2°
30.3°

Answer 1

20.3

Explanation:

Answer 2

Explanation:

u=6i-j

v=7i-4j

u.v=|6i-j||7i-4j| cos α,where α is the angle between u & v.

(6i-j).(7i-4j)=√(6²+(-1)²)√(7²+(-4)²) cos α

(6)(7)+(-1)(-4)=√37√65 cos α

42+4=√37√65 cos α

`\cos \alpha =(46)/(√(37) √(65) ) \\\alpha =\cos^(-1)(46)/(√(37) √(65) ) \approx 20.28^\circ \approx 20.3^\circ`