Question

найдите угол a{-4;1;1} и b{-1;-1;0}

Answer 1

a{-4;1;1} и b{-1;-1;0}

ab=4-1+0 =3

|a| = √( 16+1+1)=√18 =3√2

|b| = √(1+1+0) = √2

cosa=3/3√2 * √2 =1/2

a=+- π/3+2πn