Question

calcule o ângulo formado entre os vetores v (2,1,-1) e u(1,-1,-2)​

Answer 1

Resposta:

cos β = v.u/[|v|*|u|]

|v|=√(2²+1²+(-1)²)=√6

|u|=√(1²+(-1)²+(-2)²)=√6

v.u =2*1+1*(-1)+(-1)*(-2) =2-1+2=3

cos β =3/[√6*√6] =3/6=1/2

β =arc cosseno de 1/2  = 60º