where V1 and V2 a are vectors.
let K be the scalar
A vector and scalar can be multiplied but cannot be added or substracted.
scalar multiplication
V → = K < V 1 , V 2 > < K V 1 , K V 2 > \overrightarrow{V}=K<V_1,V_2>\\<KV_1,KV_2> V = K < V 1 , V 2 > < K V 1 , K V 2 >
after scalar multiplication
vector addition
let
V → = < V 1 , V 2 > U → = < U 1 , U 2 > V → + U → = < V 1 + U 1 , V 2 + U 2 > \overrightarrow{V}=<V_1,V_2>\\\overrightarrow{U}=<U_1,U_2>\\\overrightarrow{V}+\overrightarrow{U}=<V_1+U_1,V_2+U_2> V =< V 1 , V 2 > U =< U 1 , U 2 > V + U =< V 1 + U 1 , V 2 + U 2 >
scalar multiplication and vector addition
K V → = < K V 1 , K V 2 > K U → = < K U 1 , K U 2 > K ( V → + U → ) = < K ( V 1 + U 1 ) , K ( V 2 + U 2 ) > \overrightarrow{KV}=<KV_1,KV_2>\\\overrightarrow{KU}=<KU_1,KU_2>\\K(\overrightarrow{V}+\overrightarrow{U})=<K(V_1+U_1),K(V_2+U_2)> K V =< K V 1 , K V 2 > K U =< K U 1 , K U 2 > K ( V + U ) =< K ( V 1 + U 1 ) , K ( V 2 + U 2 ) >
scalar and vector addition
consider a vector v → \overrightarrow{v} v
which looks like
consider a scalar k
let say k=5
we cannot add a number to a vector