Respuesta :
Answer:
Step-by-step 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
[tex]\cos \alpha =\frac{46}{\sqrt{37} \sqrt{65} } \\\alpha =\cos^{-1}\frac{46}{\sqrt{37} \sqrt{65} } \approx 20.28^\circ \approx 20.3^\circ[/tex]
