Definition: Generally, we stipulate that the product of real number λ and vector A is a vector. This operation is called vector multiplication, and it is denoted as λ a. ..

Operating rules:

( 1)|λa|=|λ||a|。

(2) when λ >; 0, the direction of λa is the same as that of A; When λ

Precautions:

The real number λ in (1)λa is called the coefficient of vector A. 。

(2) The geometric meaning of vector multiplication operation is to enlarge or shrink A along the direction of A or the opposite direction of A. 。

(3) When λ = 0 or a = 0, λ a =. Note that it is 0, not 0.