Problemas matemáticos en las escuelas secundarias vocacionales

1)|Vector A | = √(3 ^ 2 4 ^ 2)= 5

|Vector b | = √ [(-2) 2 5 2] = √ 29

Vector a vector b = (3, 4). (-2, 5)=-6 20

=14

Entonces cos < a, b gt=(vector a . vector b)/(|vector a||vector b |)

=14/(5*√29)=14√29/145

(2)cos lt; a, b gt=(a.b)/(|a| |b|)

=-8/(√13*√5)

=-8√65/65