Vector A times vector b= (modulus length of vector A) times (modulus length of vector B) times cosα[α [α is the angle between two vectors]. Vector a(x 1, y 1) vector b(x2, y2), vector a times vector b=(x 1*x2, y 1*y2).

Vector product formula:

The vector a=(x 1, y 1) and the vector b=(x2, y2).

Ab = x1x 2+y1y2 = | a || b | cos θ (θ is the angle between a and b).

PS: Vector is not called "product", it is called quantity product. For example, a and b are called the product of a and b or the point a times b.

Development history:

Vector, originally applied to physics. Many physical quantities such as force, velocity, displacement, electric field intensity and magnetic induction intensity are vectors. Around 350 BC, Aristotle, a famous ancient Greek scholar, knew that force can be expressed as a vector, and the resultant force of two forces can be obtained through the famous parallelogram rule.

The word "vector" comes from directed line segments in mechanics and analytic geometry. Newton, a great British scientist, was the first to use directed line segments to represent vectors.